In a small bowl, mix together the hoisin sauce, sherry, soy sauce, barbeque sauce, onions, garlic and ginger. Set aside.
Preheat oil in a large skillet over medium high heat. Sear the steak bites, turning to sear all sides. Turn the heat down and pour the hoisin sauce mixture over the bites and mix well, coating the bites with the sauce. Simmer until sauce begins to bubble. Add the pineapple chunks and continue to simmer until pineapple is warm, and sauce thickens. If sauce becomes too thick, add some of the reserved pineapple juice one tablespoon at a time to achieve desired thickness. Serve over hot cooked rice. Serve hot or cold.
Alternate method: Make hoisin sauce mixture in a saucepan and simmer. Thread beef bites and pineapple (can also use fresh pineapple) on skewers that have been soaked in water for 20 minutes to an hour. Heat BBQ to medium high heat. Grill skewers for 5–10 minutes until seared on all sides. Remove from grill and place on a serving dish. Drizzle hoisin mixture over the skewers or serve sauce on the side for dipping.