Simmer first five ingredients in frypan for 20-25 min.
In separate frypan, brown ground beef. Remove from pan and reserve. To same pan, add olive oil and lightly sauté the onions & peppers in oil without overcooking.
Spoon half of tomato sauce on top of each pizza shell. Top with the pepper and onion mixture. Sprinkle on mozzarella cheese and cooked beef.