2 tablespoons butter
1 cup finely chopped onion
1/2 cup finely chopped carrot
1/3 cup finely chopped celery
1 tablespoon minced garlic
1 tablespoon Italian seasoning
2 teaspoons salt
1/2 teaspoon freshly ground black pepper
1 1/2 pounds ground beef chuck
1/2 pound Italian sausage (hot or sweet)
1 1/4 cups fresh breadcrumbs
3 eggs
1 cup ketchup, divided
1/3 cup fresh flat-leaf Italian parsley, chopped
2 tablespoons Dijon mustard
1 tablespoon Worcestershire sauce
2 tablespoons brown sugar