Instructions:

Heat oil in a large pan over medium heat. Add diced onion, bell pepper, and mushrooms. Cook until tender, about 7-10 minutes.

Add chopped garlic and cook until fragrant (about 1 minute) before removing from heat.

In a mixing bowl, combine ground beef, salt, pepper, cheese whiz (if using), Worcestershire sauce, ketchup, eggs, breadcrumbs, and the cooked onion, pepper, mushroom, and garlic mixture.