
2 lb thin-sliced top sirloin

1 large yellow onion, diced

1 tbsp avocado oil, plus more as needed

1 tbsp kosher salt

1 tsp black pepper

1 tsp garlic powder

4 hoagie rolls

6 - 8 slices Provolone cheese

4 tbsp softened butter

1 garlic clove, minced

1/2 tsp parsley, optional

8 oz American cheese, about 12 slices

1/4 cup whole milk

1 tbsp butter

1/4 tsp garlic powder

1/2 tsp Worcestershire sauce
Heat avocado oil in a skillet over medium-low heat. Add the diced onion with a little salt and pepper. Cook until caramelized, adding small splashes of water whenever the pan starts to dry out.
Thinly slice the thin sliced sirloin and season with salt, pepper, and garlic powder. Heat a little avocado oil in a hot skillet, spread the steak out, and sear for 45–60 seconds. Flip, break it apart, and cook another 1–2 minutes until just cooked through. Don’t overcook it or the steak can get chewy.
Add the caramelized onions back to the steak and mix together. Top with the provolone, let it melt, then mix the melted cheese into the steak and onions.
Slice the hoagie rolls about ¾ of the way through, keeping them attached. Mix the softened butter with the garlic and parsley, spread it over the inside of the rolls, then toast until golden.
Make the cheese whiz last so it stays warm and pourable. Add the American cheese, milk, butter, garlic powder, and Worcestershire to a small saucepan over low heat. Stir until completely melted and smooth, adding a splash more milk if needed.
Fill the toasted hoagie rolls with the cheesy steak and onions, then spoon the warm homemade cheese whiz over the top.