Turkey Sausage Meatloaf

1 large onion, chopped
2 carrots, chopped
1 cup beef broth
2 eggs
½ cup bread crumbs
2 tablespoons minced fresh basil
½ teaspoon salt
½ teaspoon ground black pepper
1 pound ground turkey
¾ pound ground beef
½ pound ground pork sausage
½ cup condensed tomato soup
1 tablespoon balsamic vinegar
½ teaspoon Dijon mustard