Stuffed Whole Cabbage Recipe

Name: Stuffed Whole Cabbage Recipe
Ingredients: 4 tablespoons (1/2 stick) butter; 1 1/2 cups finely chopped onions; 1/2 cup finely chopped shallots; 1 cup chopped leeks, white and pale green parts; 1/2 cup finely chopped peeled carrots; 1/2 cup finely chopped celery; 1 tablespoon chopped fresh thyme; 1 tablespoon minced garlic; Salt and freshly ground black pepper; 2 cups fresh breadcrumbs; 1/2 cup plain whole-milk Greek yogurt or sour cream; 1 pound ground beef (80% lean); 1/4 pound ground veal or pork; 1/2 pound mild or smoked ham, cut into 1/2-inch dice; 1/2 pound mild Italian fennel sausages, removed from the casings; 1/2 pound chicken livers, finely chopped (optional); 8 large chard leaves, stems removed, blanched in boiling water until wilted, squeezed dry and chopped; 2 large eggs; 1 large head savoy cabbage (at least 8 inches in diameter and about 2 1/2 pounds); butter; 4 bay leaves; 3-4 thick-cut bacon slices, cut in half crosswise; 2-3 cups homemade beef stock or canned low-sodium chicken broth, plus more if needed; 1 cup dry white wine (such as Vouvray); 1 cup canned crushed or pureed Italian plum tomatoes; 1 teaspoon chopped fresh thyme; 1/2 cup crème fraîche or sour cream (optional)