Drain pineapple, reserving juice and pineapple chunks. In a bowl, combine the brown sugar, cornstarch and ginger. Stir in the water, vinegar and reserved juice until smooth; set aside.
In a large nonstick skillet, saute the ham, green pepper and onion in hot oil over medium-high heat for 3 minutes or until ham is lightly browned and vegetables are crisp tender. Stir reserved pineapple chunks into skillet; heat through. Stir juice mixture. Gradually stir into skillet. Bring to a boil; cook and stir for 1-2 minutes or until thickened. Serve over rice.