- 2 leeks (2 cups), cleaned, halved lengthwise, sliced ¼-inch
- 1 head cauliflower, broken into bite-sized florets
- 2 tablespoons all purpose flour
- 2 tablespoons butter
- 4 ounces Gruyere cheese, grated
- 1⅓ cups milk
- 1 teaspoon fresh thyme, minced
- ⅛ teaspoon grated nutmeg
- 1 teaspoon salt
- ½ teaspoon epper
- 1 tablespoon butter
- 1½ cups fresh breadcrumbs (3 slices of sandwich bread or rustic bread, pulsed in a food processor)
- ¼ teaspoon salt
- ¼ teaspoon pepper
- Preheat oven to 400°F.
- Melt butter in a medium sized saucepan over medium heat. Add the sliced leeks and gently cook until completely softened, about 8 to 10 minutes.
- While the leeks are cooking, place cauliflower florets in a steamer basket in another saucepan over an inch of water. Bring water to a boil, cover, and steam the cauliflower for 4 minutes. Remove cauliflower from hot pan and set aside.
- Add 2 tablespoons flour to the leeks and butter. Cook for two minutes, stirring constantly. Slowly add milk while stirring to break up any lumps. Bring to a low simmer and continue to stir as the sauce thickens.
- Once the sauce is thick enough to coat the back of a spoon, stir in 3 ounces of the shredded cheese, nutmeg, the thyme, and salt.
- Spread a teaspoon of butter over the insides of a 2-quart gratin dish. Place the steamed cauliflower in an even layer in the dish. Pour the leek and cheese sauce over the cauliflower. Top with remaining cheese.
- Bake for 25 minutes.
- While the gratin is in the oven, melt 1 tablespoon butter in a small sauté pan over medium high heat. Add the fresh breadcrumbs and toast in the melted butter for 4 to 5 minutes, until lightly browned. Sprinkle with salt, and pepper. Remove from heat.
- After baking for 25 minutes, remove the gratin from the oven. Sprinkle toasted breadcrumbs over the top and return to the oven. Bake for 5 more minutes.