This is a recipe I got from cooks.com. I add a small onion and leave out the tomato. It usually follows a pork roast dinner, so I can use up the leftovers. The prep and cook times are for using leftovers
If using fresh pork, trim fat from meat and cut thin strips into 1" squares. Cook meat in small amount of hot oil in a large fry pan for 10 to 15 minutes or until done. Drain fat from pan.
If using cooked left over pork, trim excess fat and cut into 1" chunks. Place in a large fry pan. No need to heat.
Prepare sauce by combining all ingredients, except cornstarch in water, in a medium saucepan. Bring to a boil and simmer 1 minute. Slowly add cornstarch and water mixture and stir and cook until thickened. Add green pepper to sauce and cook 1 minute.
Transfer sauce mixture to fry pan with meat. Add tomato, pineapple and mandarin oranges and heat through. Serve over rice.