To a large Dutch oven (or heavy-bottomed pot) over medium heat, add olive oil.
Once the oil is hot and shimmering, add ground beef, onion, and diced bell peppers. Cook, breaking the meat up as you go, for 8 to 10 minutes, or until the ground beef is fully cooked and no longer pink. Drain grease if necessary.
Add garlic and cook for 1 minute, stirring constantly.
Add diced tomatoes with their juice, tomato sauce, beef broth, water, Worcestershire sauce, salt, black pepper, and Italian seasoning. Stir well to combine.
Bring the soup to a boil, then reduce the heat to low.
Stir in the orzo pasta. Then, cover and simmer for 12 to 15 minutes, stirring occasionally, until the orzo is tender and the soup has thickened slightly.
Remove the pot from heat.
Garnish with chopped parsley before serving. Serve warm.