1-First, prepare all ingredients by placing the sirloin in the freezer for 20 to 30 minutes to make slicing easier. Then, thinly slice the onions and bell peppers for even cooking. This step helps everything come together quickly and smoothly.

2-Next, heat 2 tablespoons of vegetable oil in a large, deep sauté pan over medium-low heat. Sauté the sliced onions and bell peppers until they’re tender, which takes about 10 minutes, and set them aside. This builds a flavorful base without browning the veggies too much.

3-After that, remove the beef from the freezer, trim any excess fat, and slice it as thinly as possible against the grain. Chop it into small ¼-inch pieces for the best texture. Then, return the pan to medium-high heat and add the remaining 2 tablespoons of vegetable oil.

4-Cook half the beef with ¾ teaspoon of seasoned salt and ½ teaspoon of garlic pepper until it’s browned and no pink remains, about 3-4 minutes. Transfer it to the dish with the vegetables and repeat with the rest. Preheat your oven to 400°F (200°C) while you work.

5-Once the beef is done, split the hoagie rolls without separating the halves and spread softened butter inside each one. Place them on a baking sheet and toast for 3 to 5 minutes until lightly golden. Finally, drain excess juices from the pan, return everything to it, arrange the provolone slices on top, cover, and cook over medium heat until the cheese melts, about 4 to 5 minutes. Stir it all together and fill the rolls.