In skillet brown Spam in oil,remove.Saute onion and peppers in remaining oil, until almost tender. Return Spam to skillet.Drain syrup from pineapple,add water to make 1 1/2 cup of liquid. Add pineapple to skillet.
Combine pineapple liquid,vinegar,sugar,cornstarch,soy sauce and ginger; add to skillet.Simmer until sauce thickens,stirring constantly, about 3 min. Serve over rice.