1 large head cauliflower, separated into bite-sized florets
10 cups water
1 cup milk
For the sauce:
3 tbsp butter
3 shallots, finely minced, about 4-5 tbsp
3 cups cauliflower stem and trimmings, small 1/2-inch dices
3 cups whole milk
1 bay leaf
1 tsp dried thyme
1/4 tsp freshly grated nutmeg
black pepper, to taste
salt, to taste
1/2 cup Emmental/Swiss cheese, grated
1/4 cup bread crumbs
Preheat your oven to 400-430 °F.
Bring a large pot of water to a boil. Add the water, salt and milk. Precook the cauliflower florets for 5 minutes. Drain and set them aside.
For the sauce
In a saucepan, heat 3 tbsp of butter over medium heat, add the shallots and sweat them for 2-3 minutes.
Add the cauliflower stem and trimmings and sweat the mixture for 1-2 more minutes.
Add the milk, bay leaf, thyme, nutmeg, black pepper, and 1/2 tsp salt.
The milk should cover the cauliflower pieces completely (you can add more enough to cover them). Bring the mixture to a simmer and let it cook over low flame for about 5 minutes .
Once the cauliflower pieces have lightly softened, transfer the sauce into a blender and puree until smooth. If the sauce turns out too thick for your liking, adjust the consistency by adding more milk. Season the sauce to taste with salt.
In a casserole dish, mix the precooked cauliflower florets with the sauce.
Sprinkle with Emmental/Swiss cheese and bread crumbs.
Bake the gratin in the preheated oven for 25-30 minutes. Once the gratin is ready, turn on the broiler to lightly brown the top for 3-4 minutes.