Return the beef and pineapple to the skillet. Whisk the sauce to recombine then add to the skillet. Cook, stirring constantly, until the sauce is thickened, the beef is cooked and vegetables are crisp tender, about 1-2 minutes. Stir in about half of the green onions. Taste and add additional Asian chili sauce, sweet chili sauce
, etc. if desired. Serve with rice and garnish with remaining green onions.