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