Pat the ribeye dry and season with salt and pepper. For super-thin slices, freeze the steak for 20 minutes before slicing.

In a large skillet, melt butter with 1 tablespoon olive oil over medium heat. Add onions and cook, stirring occasionally, until golden brown, about 10 minutes. Transfer onions to a plate.

Increase heat to medium-high, add remaining olive oil, and lay steak strips in a single layer. Cook for 2 minutes per side until browned but still juicy. Return onions to the skillet and toss with steak.

Reduce heat to low. Lay provolone slices over the steak mixture, cover, and let cheese melt, about 1–2 minutes.

Split hoagie rolls and toast briefly if desired. Spoon the cheesy steak into rolls, add a swipe of mayo or Cheez Whiz for extra creaminess, and serve hot.