These make-ahead Baked Crepes can be assembled the day before, then warmed up in a baking dish just as your guests arrive. Deliciously savory and hearty, they will satisfy and delight. Use this recipe as a jumping-off point for your own delicious fillings.
2 medium leeks, sliced into 1/8-inch rings (white and light green parts only). If leeks are very dirty, place rings in a bowl of cool water to loosen dirt, swish with your hand, strain, and repeat if necessary.
Make the crepes. In a medium bowl stir together the flour and the salt. In another smaller bowl, whisk the eggs and milk, then add this to the flour and beat until smooth. Stir in the melted ( but cooled) butter.
Heat a lightly oiled 8-10 inch non stick frying pan over medium-high heat. Pour 3-4 tablespoons of the batter into the pan and tilt the pan with a circular motion so that the batter coats the surface evenly and thinly. Cook the crepe for about 2 minutes, until the bottom is golden brown. Loosen with a spatula, turn, and cook the other side. (Check to see that the diameter of this first crepe fits nicely into your baking dish and adjust size if necessary.) Make the rest. Stack and set aside or make ahead and refrigerate. You should have 8–10 crepes – and it’s ok if they are not perfect!
Make the filling. Heat the butter and oil in a very large skillet or Dutch oven over medium heat. Add leeks and sauté 3–4 minutes, until just tender. Add mushrooms and continue cooking until mushrooms are tender, about 4–5 more minutes. Add asparagus and continue cooking, stirring occasionally for 3–4 minutes until they are just tender yet still vibrant green. Season with salt, pepper, and nutmeg. Stir in fresh tarragon. Set 1 cup aside (this will be used for the garnish).
To the remaining, stir in the goat cheese and the ricotta. Taste and adjust salt.
Divide filling among crepes and roll them up. Arrange into a large, greased baking dish (or two medium sized) and place in a 350°F oven until warmed through, about 20–25 minutes. These can be assembled ahead, refrigerated, and heated before serving. (Bring them to room temperature first). If you prefer very soft crepes, cover with foil. If you like them a little crisp, uncover, or uncover part way through.
Right before serving, heat up the remaining cup of asparagus mix in a small sauce pan, drizzle with optional truffle oil, and spoon over the center of crepes. Garnish with a few more tarragon leaves.