Ingredients

3 tablespoons vegetable oil, plus more as needed
4 medium red onions, sliced into 1/4-inch thick rounds
Salt and pepper
2 pounds top round, semi-frozen
1/2-pound fontina cheese, cut into small cubes
4 sub rolls

Instructions

Heat 3 tablespoons oil in a nonstick skillet over high heat. Saute
the onion slices until wilted and just starting to take on some color, stirring all the while, about 7
minutes. Sprinkle onions with salt while cooking.

Slice the top round into very thin slices. Partially freezing the meat enables you to slice it very thinly.

Remove the onions from the skillet. Salt and pepper the steak slices and then saute them in the same skillet,
in batches until cooked through, about 45 seconds per side. Repeat process for the remaining steak slices,
replenishing oil as needed.

Meanwhile, melt the cheese cubes in a microwave-safe bowl on low power for a couple minutes or until
completely melted.

Cut each roll down the middle lengthwise. Fill each roll with a good helping of steak slices and top with the
melted cheese and sauteed onions.