Heat oil in a large skillet until very hot. Add the meat and stir-fry until nicely browned. Add the onion, water, garlic salt, and ginger. Bring mixture to a boil, cover and cook for about 5 minutes. Add the bell peppers, cover, and cook about 5 more minutes, or until the peppers are tender. Add the tomatoes.
Combine the sugar, corn starch, and soy sauce in a bowl and whisk together until well combined. Add this mixture to the meat and pepper mixture and bring to a boil. Continue to cool, uncovered, until the sauce thickens.
Serve over steamed rice.
Submitted by: Frank K.