1. Caramelize. In a large skillet over medium heat, melt 1 tablespoon butter. Add the onions and bell peppers and sauté for 15 minutes, adding splashes of water as needed. Once caramelized, season with salt and transfer to a bowl.
2. Brown the meat. Melt a tablespoon of butter over medium heat in the same skillet you cooked the veggies in. Add the steak and cook for 3-4 minutes undisturbed. Season with salt and pepper, flip, and continue to cook, using a spatula to break it up.
3. Combine. Once the meat is cooked through, turn off the heat and stir in the veggies.
6. Make the cheese whiz. To a saucepan over medium-low heat, add the cheeses, cornstarch, seasoning, and evaporated milk. Bring the mixture to a very light boil, stirring consistently, then turn off the heat. Stir 1/2 cup of the sauce into the meat mixture.
5. Toast. Turn the oven to broil. Divide the. sliders in half and toast face up under the broiler.
6. Melt. Divide the steak mixture evenly over the bottom bun, top with Provolone cheese, and broil until the cheese has melted.
7. Make the garlic butter. Whisk together the garlic, parsley, and melted butter.
8. Finishing touches. Close the sliders with the top buns and brush the tops with garlic butter.
9. Serve. Slice your creation into individual sliders and serve with extra cheese whiz for dipping.
