Tortellini without syrup broth

1 lb Italian sausage (casing removed) 1 cup onion , chopped 2 large garlic cloves , minced 5 cups beef stock 2 cups chopped tomatoes 1 (8 ounce) can tomato[...]

4 tablespoons olive oil 2 onions , finely chopped 2 carrots , finely chopped 2 celery ribs , finely chopped 4 garlic cloves , finely chopped 1 lb ground beef[...]