Add onion, peppers, garlic, ground beef, dry mustard, chili powder, salt and pepper in a skillet with olive oil. Sauté until ground beef is browned and stirring as it cooks to ensure beef is broken up.
Add rice and tomato paste and cook for 3 minutes.
Add canned tomatoes and juice, water, and Worcestershire sauce. Simmer for 20 minutes, covered.
Remove lid after 20 minutes and fluff with fork. If mixture is soupy or wet cook for an additional 2 minutes uncovered.