Salty and rich, this cauliflower cheese casserole makes enough for a hearty vegetarian main dish along with a fresh salad. Two kinds of cheese including sharp cheddar and Parmesan, add loads of flavor.
Wash and break the 1 large cauliflower into large florets. Bring a large pot of salted water to a rolling boil and drop in the florets. Boil the florets for about 5-8 minutes or until they are tender when pierced with a knife. Pour the florets carefully through a colander to drain.
Meanwhile, in a heavy saucepan over medium heat, melt the 6 tablespoons unsalted butter. Whisk in the 6 tablespoons sweet white rice flour and cook over low heat, stirring, for about 2 minutes until a thick paste forms. Gradually pour the 2 ⅔ cups whole milk into the roux whisking constantly. Bring the sauce to a simmer and simmer, whisking, for about 5-10 minutes, until the sauce is very thick. Stir in all but a small handful of the ½ cup extra-sharp cheddar cheese and ½ cup grated parmesan cheese, the 1 teaspoon fine sea salt and ½ teaspoon pepper, and½ teaspoon dried thyme.
Arrange the florets in a baking dish, scatter the drained 1 can butter beans over the top, and pour over the cheese sauce over the entire dish. Scatter the surface with the rest of the cheese.
Place in the oven and bake for 30 minutes or so or until the sauce is bubbling at the edges. Remove, let stand for 5 minutes, and eat hot.