Heat a large Dutch oven or soup pot over medium heat. Add the ground beef and diced onion, breaking the beef into small pieces as it cooks for about 5 to 7 minutes, until it is no longer pink. Drain excess grease if needed.

Add the diced green and red bell peppers and minced garlic. Cook for 2 to 3 minutes, stirring often, until the peppers begin to soften and the garlic smells fragrant.

Stir in the undrained diced tomatoes, tomato sauce, beef broth, Italian seasoning, kosher salt, black pepper, and Worcestershire sauce. Scrape the bottom of the pot so any browned bits blend into the broth.

Bring the soup to a boil, then reduce the heat to low. Partially cover the pot and simmer for about 15 minutes so the broth develops a rich tomato and beef flavor.

Stir in the uncooked long-grain white rice. Continue simmering for 15 to 20 minutes, stirring occasionally, until the rice is tender and the peppers are soft.

Taste the soup and adjust the seasoning as needed. If it becomes too thick, stir in a little extra broth or water, then garnish with chopped parsley and serve hot.