Slice the slider buns horizontally but keep them connected.
In a large skillet, melt 2 tbsp butter with olive oil over medium-high heat.
Add the sliced onions and bell peppers. Cook until softened, about 5-7 minutes. Season with salt and pepper. Remove from skillet and set aside.
Add the thinly sliced ribeye steak to the same skillet. Cook until browned, breaking it apart with a spoon. Season with salt and pepper.
Drain any excess grease from the steak.
Return the onions and peppers to the skillet with the steak. Stir to combine.
Place the bottom halves of the slider buns on a baking sheet.
Spoon the steak and vegetable mixture evenly over the bottom buns.
Top the mixture with provolone cheese slices or drizzle with cheese sauce.
Place the top halves of the slider buns over the cheese.
Brush the tops of the buns generously with melted butter.
Cover the baking sheet tightly with aluminum foil.
Bake for 15-20 minutes, or until the cheese is melted and the buns are heated through.
For crispier bottoms, remove the foil for the last 5 minutes of baking.
Slice between the buns to serve individual sliders.
Notes
To make ahead, assemble the sliders and cover tightly with plastic wrap, then foil. Refrigerate for up to 24 hours. Bake covered for 25-30 minutes, then uncover for the last 5 minutes.
If using cheese sauce, warm it slightly before drizzling over the filling for easier spreading.
For a game day slider board, arrange the baked sliders on a platter with dipping sauces like ketchup or mustard.
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