Cauliflower baked with goat cheese is a lush combination; orange juice gives surprising zing, and prosciutto and fresh thyme add more flavor.
Preheat oven to 375 degrees. Butter a 2-quart casserole or an 8-inch square baking dish; set aside. Bring a large pot of water to a boil. Add cauliflower; cook until just tender, 4 to 5 minutes. Drain.
Whisk together 8 ounces goat cheese, the orange juice, stock, thyme, flour, 1 1/2 teaspoons salt, and 1/2 teaspoon pepper until smooth. Toss in cauliflower and prosciutto. Spoon into buttered dish. Top with remaining 4 ounces goat cheese.
Cover with foil; bake 30 minutes. Remove foil; bake until bubbling and just golden, about 30 minutes more. Let cool slightly before serving.