In a mixing bowl, combine the ground beef, breadcrumbs, diced onion, diced bell pepper, diced pineapple, teriyaki sauce, egg, garlic powder, salt, and pepper. Mix well until all ingredients are evenly incorporated.
Form the mixture into patties according to your preferred size.
Preheat the skillet or grill over medium-high heat and grease it with a small amount of cooking oil.
Place the patties on the skillet or grill and cook for about 4-5 minutes on each side or until they reach your preferred level of doneness.
While the patties are cooking, you can brush them with additional teriyaki sauce for extra flavor.
Once done, remove the chopped steak patties from the heat and let them rest for a few minutes.