01 - Melt half the butter in a medium skillet over medium-high heat. Add sliced onion and bell pepper, sautéing for 2-3 minutes until they begin to soften.
02 - Add the sliced steak and cook, stirring occasionally, until browned and just cooked through, about 2 minutes. Season with half the salt, pepper, and garlic powder. Remove the filling from the skillet and set aside.
03 - Wipe the skillet clean and reduce heat to medium. Whisk together eggs, milk, and the remaining salt, pepper, and garlic powder.
04 - Melt the remaining butter in the skillet. Pour in the egg mixture and cook undisturbed until the edges start to set, about 1-2 minutes.
05 - Gently lift the edges and tilt the pan to allow uncooked eggs to flow underneath. When nearly set, add the steak, peppers, onions, and provolone cheese to one half of the omelette.
06 - Fold the omelette over the filling and cook for another 1-2 minutes until the cheese is melted and the omelette is cooked through.
07 - Slide onto a plate, garnish with parsley if desired, and serve hot.