Creamy Cauliflower Gratin with Whole Wheat Crumbs

Name: Creamy Cauliflower Gratin with Whole Wheat Crumbs
Ingredients: Two 2 1/2-pound heads of cauliflower, cut into 2-inch florets; 2 tablespoons extra-virgin olive oil; 3 garlic cloves, minced; 4 anchovy fillets, mashed to a paste; 6 medium scallions, thinly sliced; 1 cup chicken stock or canned low-sodium broth; 2 cups heavy cream; 1 1/2 cups fresh whole wheat bread crumbs; 3 tablespoons freshly grated Parmesan cheese; 1 tablespoon unsalted butter, melted; Salt and freshly ground pepper