Roast Head of Cauliflower in Creamy Mushroom Sauce

Name: Roast Head of Cauliflower in Creamy Mushroom Sauce
Prep time: 10 min
Cook time: 50 min
Total time: 1 h
Ingredients: 2 tablespoons butter; 1 small onion, diced; 8 ounces cremini mushrooms, sliced; 2 cloves garlic, chopped; 1 teaspoon thyme, chopped; 1/4 cup dry white wine (or broth); 1/4 cup vegetable broth or chicken broth; 1/2 cup cream; 1/2 cup parmigiano reggiano (parmesan), grated; 1 tablespoon white miso paste (optional); salt and pepper to taste; 1 large head of cauliflower; 1 tablespoon oil; 1/2 cup gruyere, shredded (optional)