Trim separable fat from round steak. Partially freeze meat; then, cut on bias into thin bite-size strips. Drain pineapple, reserving juice. Cut pineapple slices into quarters; set aside.
In a bowl stir together reserved pineapple juice, dry sherry or water, soy sauce, molasses or brown sugar, and red pepper. Add meat; stir until coated. Cover and marinate meat at room temperature for 15 minutes. Drain, reserving marinade.
Spray a cold large skillet or wok with nonstick cooking spray. Add half of the meat to skillet or wok. Stir-fry for 2 to 3 minutes or until browned. Remove meat. Stir-fry remaining meat and onions for 2 to 3 minutes or until meat is browned. Return all meat to skillet. Push meat from center of skillet.
For sauce, stir cornstarch into reserved marinade. Add sauce to center of skillet. Cook and stir until thickened and bubbly. Add tomato, pea pods, and pineapple. Stir ingredients together until coated with sauce. Cook and stir about 2 minutes more or until heated through. Serve over hot cooked rice. Makes 4 servings.