Butternut Squash Gratin with Leeks, Sage and Walnuts – a delicious vegetarian side dish, highlighting the best of fall ingredients, worthy of the holiday table! Vegan-adaptable. With a Video!
We can’t decide what we like best about this Butternut Squash Gratin- the melted leeks, the toasted walnuts, the fresh sage, or the hint of nutmeg that infuses the whole thing with goodness.
Think of this like scalloped potatoes, but made with butternut squash instead. Hearty and satisfying, this is pure and total comfort food.
I suppose one might categorize this as a Thanksgiving side dish and yes- that is what it was designed for, but truth be told, we’ve been eating this for “dinner” the last few nights, along with a salad and sourdough bread and couldn’t be happier. Use it as you please.
The recipe makes a big batch- enough to serve eight, so feel free to cut this in half for smaller gatherings.
Butternut Squash Gratin Video
Ingredients in Butternut squash Gratin:
- Butternut squash
- Leeks
- Fresh Salad
- Gruyere cheese (or vegan parmesan cheese)
- heavy cream ( or plant-based cream, milk or coconut milk)
- nutmeg
- walnuts
How to make Butternut Squash Gratin:
Start by preheating the oven to 375F and peeling the butternut squash.
Slice as thinly as possible- aiming for 1/8 of an inch. The thinner the slices the faster this will cook.
When you get to the seeds, scoop them out and keep slicing.
We will hide the half-moons in the middle layer of the gratin.
Slice the leeks, rinse well, and saute until meltingly tender.
Add the fresh sage leaves.
Mix up the heavy cream with the seasonings.
Here we are using heavy whipping cream, feel free to use half and half or plant-based cream or coconut milk if you like.
Then begin layering all the ingredients.
Grease a 9×13 inch baking dish, or a shallow round 11-12-inch baker like you see here. TIP: A large shallow baking dish is key here to getting this to bake evenly and quickly.
Add 1/4 cup water to the greased baking dish. Then start layering the butternut and 1/2 of the leek mixture. Top with cheese and 1/3 of the cream sauce.
For the middle layer, add all the scraps and half moons, saving the prettiest slices for the top layer.
Sprinkle with leeks and cheese and a little of the cream mixture.
Here below is the top of the second layer. I’ve hidden all the misshapen pieces of butternut in this middle layer.
Top with the final layer of butternut slices- layering a little if need be.
Spoon the remaining cream mixture over top.
Sprinkle with cheese and the toasted walnuts.
And if you like, add an additional sprinkling of freshly grated nutmeg.
Cover tightly and bake for 45 minutes.
Then uncover, turning the heat up to 4oo for 10-15 more minutes until beautifully golden
Garnish with crispy sage leaves if you like.
Can this be made ahead?
Yes, this can be assembled ahead and baked the day of serving, bringing it to room temp before baking. Alternatively, this can be baked ahead and reheated in a low 325-350F oven, covered (also bringing to room temp before reheating).
Can this be frozen?
Probably. My hesitation is it might get watery- but only guessing here. If you freeze this, please report back and let us know in the comments.
Can this be made vegan?
Yes, I think so! Use vegan parmesan and a vegan cream or plant-based cream. Lite Coconut milk from a can would taste good, I bet. Please let us know if you try this- leaving notes for others- thanks!!!
Give this Butternut Squash Gratin a try this Thanksgiving and let us know what you think (or ways you adapt it) in the comments below.
Cheers,
More recipes you may like:
- 25 Vegan & Vegetarian Side Dishes
- Parsnip Gratin with Gruyere and Thyme
- Cauliflower Gratin with Garlic and Sage
- Tomato Zucchini Gratin
- Butternut Lasagna with Mushrooms and Sage
Butternut Gratin with Leeks, Sage and Walnuts
- Prep Time: 40 mins
- Cook Time: 60 mins
- Total Time: 1 hour 40 minutes
- Yield: 8 1x
- Category: side dish, vegetarian
- Method: baked
- Cuisine: American
- Diet: Vegetarian
Description
Butternut Squash Gratin with Leeks, Sage and Walnuts – a delicious vegetarian side dish, highlighting the best of fall ingredients, worthy of the holiday table! Vegan-adaptable!
Ingredients
- 2 lb butternut squash, peeled, sliced to 1/8 inch disks.
- 2 tablespoons olive oil or butter
- 2 medium leeks, thinly sliced
- 4 garlic cloves, rough chopped
- 15 sage leaves, chopped (8 more for crispy sage leaf garnish- optional)
- ——
- 1 cup heavy cream (or sub coconut milk)
- 1/2 teaspoon salt and pepper
- 1/2 teaspoon nutmeg
- 1/2 teaspoon onion powder, optional
- ——-
- 1/4 cup water
- 3 ounces gruyere cheese (or sub parmesan or vegan parmesan)
- 1/2 cup walnuts, chopped
Instructions
Preheat oven to 375 F
- Prep Butternut: Peel and thinly slice the butternut squash into 1/8 -inch thick rounds. When you get to the seeds, scoop them out and continue slicing. Set aside 12-15 of the “prettiest” slices for the top of the gratin. ( There will be 3 layers of butternut – so you could divide into 3, placing any misshapen pieces in the middle layer)
- Cook the Leeks: Slice and rinse the leeks- the moisture here will help them soften. Heat oil or butter in a large skillet over medium heat. Saute the leeks, for 8-10 minutes, covering part way through so they soften. Add the garlic, sage and a pinch of salt, cook 2-3 more minutes. Turn heat off.
- Whisk the cream with the salt, pepper, nutmeg and onion powder in a medium bowl.
- Layer: Grease a large 9 x 13-inch baking dish or 11-12 inch round baking dish. A big shallow pan is BEST here ensuring even cooking. Grease the pan, add 1/4 cup water to the bottom of the pan. Layer with Butternut squash overlapping slightly. Sprinkle with half of the sauteed leeks. Drizzle with 1/3 cup cream mixture. Sprinkle with one ounce of Gruyere (about 3-4 tablespoons grated). Add the 2nd layer of butternut- using up any misshapen pieces here. Scatter with the remaining leeks. Drizzle with 1/3 cup cream mixture and sprinkle with grated gruyere cheese. Add the final layer of butternut, overlapping and pressing down so not domed in the middle. Drizzle the remaining cream mixture over top, lightly sprinkle with cheese and the walnuts. Give the pan a little shake, press down in the center again so gratin is level, not domed. Cover, using parchment first as a barrier, under the foil if the foil touches the top of the gratin.
- Bake 45 minutes covered. Uncover, confirming the butternut is tender using the tip of a knife, then bake at 400 F uncovered, 15 minutes until beautifully golden.
- To make the crispy sage leaf garnish, heat 1-2 tablespoons oil or butter in a pan over medium heat, add 8 whole sage leaves, saute each side 30 seconds or so until crisp (try a tester first) and place on a paper towel to cool for a couple of minutes. Arrange over the gratin.
Notes
This can be made ahead: Assemble ahea, refrigerate, and bake the day of serving, or alternatively, assemble and bake ahead, reheating the day of serving (350F, covered). Make sure to let this come to room temp before baking or reheating for most even cooking.
I have not tried this with cubed butternut, but if I were to go that route, I would toss them in a big bowl, with the cream mixture and leeks and cheese. Bake in a large shallow baking dish and allow 20-30 more minutes additional baking time depending on the size of the cubes. Thinly sliced butternut makes this bake relatively quickly- cubes would take longer, so plan accordingly. (Or you could lightly steam or cook them first?)
Nutrition
- Serving Size: - used heavy whipping cream and olive oil
- Calories: 201
- Sugar: 4.3 g
- Sodium: 239.5 mg
- Fat: 12.7 g
- Saturated Fat: 6.1 g
- Carbohydrates: 19.3 g
- Fiber: 3.1 g
- Protein: 5.4 g
- Cholesterol: 28.7 mg
Made this Butternut gratin with leeks for the 3rd time now. Just love it! I used coconut milk to keep it vegan and is creamy and delicious. Great flavour combinations as always from Sylvia. Easy to prepare too. Fast becoming our new midweek staple!
I made this last night and it was delicious! I will definitely be making this again and is the perfect dish for a special dinner. I used toasted sunflower seeds as I did not have walnuts, and it worked quite well.
This butternut squash gratin was superb. I plan on including this in my Thanksgiving spread moving forward. The addition of walnuts adds great texture to the dish – coming from someone who is not a nut lover. I will make this again and again.
do you think this would be good with rosemary if i can’t find sage readily? thank you so much !
I made the vegan version for Thanksgiving and it was perfection. A nice sweet side dish.
I found this recipe around Thanksgiving time, and tonight is my third time making it! It is an absolute hit. I have to eat gluten-free, and one of my flatmates has to eat dairy-free so finding delicious recipes has been a little more challenging, but this one is basically perfect 😁 I made it for family Christmas and it was the most complimented dish there!
I make it vegan with one whole tin of coconut cream, and have been just omitting the cheese but tonight I blended about a teaspoon of nutritional yeast flakes into the coconut cream for a cheesy flavour.
Thanks for sharing, great to hear!
I love this gratin! Have made it a few times now as a lovely warming winter meal. My husband loves it too. I use coconut cream as suggested and comes out beautifully creamy and delicious. Thanks Sylvia for another classic!
LOVED THIS!
will now be part of our standard celebration meal menu
This was an easy yet decadent side dish for our small Quarantine Christmas! I doubled the cheese.
Wasn’t sure if I should chop the sage as the recipe didn’t specify, but the photos gave me the impression that I should. Couldn’t hurt to edit the recipe if this is the case.
Thanks, fixed it. 😉
This was SO good! My family was not really looking forward to trying this dish, but it was universally liked and they asked for the recipe. I used a sweet meat squash instead. It was a pain to peel, but I didn’t lose any fingers, so all good. Thank you
Delicious! I made ours with half and half and heavy cream. Turned out great!
Made this and added panko on top because my family is all about crunch.What a winner! We swooned, we ooh’d and paired it w/ a simple salad and nice cava. Another favorite recipe from Sylvia!
So delicious that I stopped everything I was doing to analyze all the incredible flavors swirling around. Thank you so much Sylvia.
this was so delicious! made it vegan using coconut cream and skipped the cheese altogether. it was a winner!!
Oooooo love it! How much coconut milk did you add? Did you add water too? Thanks Paloma!
i used half a cup of coconut cream, it’s really thick like full fat cream so I mixed in about half cup of water (the texture turned out to be basically coconut milk). I also added water to the bottom of the pan but would skip this step next time because it came out watery at the bottom after cooking.
Thanks appreciate this!
Hi
I made this with coconut milk but the receipe was very watery. Is the additional water necessary with coconut milk?
Probably not, sorry.
This was SO GOOD! My husband made it for thanksgiving to go with our slow roasted goose and I’m now going to insist we cook it every year. It easily substitutes both mashed potatoes and yams—yum!
The ultimate cosy supper dish on a cold, dark and windy evening. Tasted amazing and the toasted walnuts added a lovely interesting texture. Used dried sage as couldn’t get fresh and served with salad and bread! Sublime! Thanks Sylvia
Divine!! Easy to make and such great presentation and flavour – the butternut is the key. Thanks again Sylvia, love your recipes✨
Another awesome recipe! I didn’t have any gruyere so used smoked cheddar instead. The leeks blended in so well with the smooth squash. There was a hint of nutmeg with the smokiness of the cheese. The walnuts were the icing on the cake. We ate this for dinner and it was so satisfying. Thanks again. I look forward to your recipes each week
OMG, sooooo good ! I did not have fresh sage, so i use sage pesto i had frozen. This will be redone again and again for sure. Thanks for all your great recipes, you are one of my best recipes website, if not the best !
Hi Sylvia…can you use Sweet potato’s instead of squash. I’m already making a squash dish and would like to use sweet potato’s in an interesting way.
I bet it would taste good with sweet potatoes too!
Can’t wait to make this!
Will try the butternut squash recipe.
Are there any options to not use so much fat in the recipes.
It’s just better for me health wise.
What if you used whole milk or nut milk?
So good! I didn’t know what to expect from this recipe. I’ve never cooked with leeks or fresh sage before and I don’t often use special cheeses. But everything came together very easily. I didn’t worry about arranging the squash just so – I used my kitchenaid slicer to whip through the veggies and so it wasn’t super pretty, but it worked well and it looked just fine in the end under the cheese. 🙂 I don’t suggest any tweaks – it was excellent. I’ll definitely be making this again.
Thanks so much and glad you liked this!
I’m really excited to make this for parties and dinners once things have settled down again. It looks delicious, and the vegetarian substitutions sound great! Quick question, how many walnuts did you use in this recipe? The directions don’t include how much, just that they were sprinkled in. Thank you!
Oooops! 1/2 cup walnuts- thanks, I added. 🙂