Heat the olive oil in a large Dutch oven or soup pot over medium heat. Add the diced onion and sauté for 3-4 minutes until softened.

Stir in the minced garlic and cook for another minute until fragrant, being careful not to burn it.

Pour in the beef broth and crushed tomatoes. Add the Italian seasoning, salt, and pepper. Stir to combine and bring the mixture to a gentle boil.

Reduce the heat to medium-low. Carefully drop in the beef meatballs. Cover and simmer for 10-15 minutes until the meatballs are heated through (if using frozen) or cooked (if using fresh).

Add the cheese tortellini to the pot. Simmer for 3-5 minutes, or according to the package instructions, until the pasta is tender.

Taste and adjust seasoning if necessary. Ladle into bowls and serve immediately, topped with grated Parmesan cheese and fresh parsley.