Truffled Macaroni Cauliflower Gratin

Name: Truffled Macaroni & Cauliflower Gratin
Ingredients: Serves 6; 12 ounces elbow pasta; 1/2 head cauliflower, cut into florets (optional); Salt, to taste; 6 tablespoons butter; 3/4 cup bread crumbs, preferably panko; 1 cup grated parmesan; 1/4 cup flour; 3 1/2 cups milk; 1 1/2 cups grated gruyère; 1 1/2 cups grated comté; 3/4 cup grated grated fontina; 3/4 cup grated appenzeller; 1/4 ounce (or to taste) fresh black truffle, grated; Freshly ground black pepper, to taste