In a bowl mix together the thinly sliced beef with olive oil, vinegar, baking soda, sugar, garlic powder, paprika, onion powder, minced garlic, black pepper, salt, and Worcestershire sauce.
In a medium skillet on high, add in the sliced onions, green peppers and sauté for about 4 minutes. Add in the mushrooms and the marinated beef, sear for another 3-4 minutes until cooked.
Preheat oven to 350 F.
Place the bottom layer of the sliders in a 9x16 baking dish. Spread the sautéed meat and veggies all over, then place the sliced cheese on top of the meat. Cover with the top slider buns.
Mix together the butter spread ingredients. Brush the top of the KING’S HAWAIIAN® Slider Buns with spread. Bake for 15 minutes. Enjoy warm!