Preheat oven to 325 degrees F (160 degrees C).
Halve the Bell Pepper (4).
Place peppers in a large baking dish and bake until tender, 30 minutes.
Slice the Onion (1).
Slice the Cremini Mushroom (16 ounce).
Thinly slice the Sirloin Steak (1.5 pound).
Heat Vegetable Oil (1 tablespoon) in a large skillet over medium-high heat. Add onions and mushrooms and season with Kosher Salt (to taste) and Freshly Ground Black Pepper (to taste). Cook until soft, 6 minutes.
Add steak and season with more Kosher Salt (to taste) and Freshly Ground Black Pepper (to taste). Cook, stirring occasionally, 3 minutes. Stir in Italian Seasoning (2 teaspoon).
Add Provolone Cheese Slices (16) to bottom of baked peppers and top with steak mixture. Top with another piece of provolone and broil until golden, 3 minutes.
Chop the Fresh Parsley (to taste).
Garnish with parsley before serving. Enjoy!