To prepare a steaks mushroom sauce and cauliflower puree recipe, combine the following ingredients: 2 tablespoons butter, 2 teaspoons thyme, 1 teaspoon kosher salt, 1/2 teaspoon cayenne pepper, 1/4 teaspoon ground black pepper. Heat the butter over medium-high heat. Add the mushrooms and cook, stirring frequently, until they are browned, about 5 minutes. Remove from the heat and stir in the sour cream. Season with salt and pepper to taste.