1. Heat oven to 450 degrees F. Place oven shelf in top third of oven. Lightly oil 13 x 9 x 2-inch casserole.
2. Mix crumbs and milk in large bowl. Let soften, 2 minutes. Add eggs, meat, tomato sauce, salt, oregano, basil, nutmeg and pepper. Shape into meatballs, 1/4 cup each. Place in casserole; brush with oil.
3. Bake in 450 degrees F oven for about 25 minutes, until browned. Pour off any excess fat. Mix broth, tomatoes and tomato paste. Add to casserole.
4. Bake, covered, in 450 degrees F oven 1 hour. Remove meatballs to platter. Pour braising liquid into saucepan.
5. Stir together cornstarch and 3 tablespoons water in small bowl. Whisk into braising liquid. Bring to boiling over medium heat, whisking, until thickened, 1 minute. Combine meatballs and thickened liquid in casserole.