1. In a stand mixer or in a large bowl, mix yeast and milk together. Whisk in the egg, oil, salt , then stir in the flour and knead for five minutes.  The dough should be semi-soft, not stiff.
2. Oil the boil and the ball of dough, placing it back in the bowl. Cover with a damp kitchen towel and let it rise until doubled, about 1 – 1 1/2 hours.
3. In the meantime, cut, rinse and saute the leeks with the oil in a large skillet over low heat. The moisture from rinsing them will help soften them. Add the garlic, thyme, and salt and pepper. When the garlic is fragrant and the leeks are tender, turn the heat off and let this cool.
4. Preheat oven to 350F
5. When dough has doubled, place it on a well-floured surface and roll it into roughly a 12-inch by 16-inch rectangle. Spread out the tender, seasoned leeks and sprinkle with cheese. Make sure to use at least 2 kinds of cheese here for the best flavor – adding a melty cheese like mozzarella- and make doubly sure you salted your leeks in the pan. 🙂
6. Starting from the narrower end, roll into a roll. Fold the ends under and place on of parchment- lined sheet pan.
7. Cut little “beaks” into the dough (refer to photos) at a 45-degree angle, 2/3 rds of the way deep at one-inch intervals. Then pull the points out towards the edges, alternating sides. (See photo above.) Cover with a towel and let rest 20 minutes.
8. Make the egg wash by whisking the egg, water and salt in a small bowl. Brush the dough gently with egg wash. (Or use butter or half and half).
9. Place in the hot oven, on the middle rack, uncovered. Check at 20 minutes (rotating if need be) and continue baking until puffed and golden for an additional 20-30 minutes until beautifully golden. NO pale loaves please. 🙂 Internal temp should be at 200F.

Enjoy! Your home will smell amaaaaaaazing!