Heat half the butter in a skillet over medium heat. Add in the onion and red bell pepper. Season with salt and pepper. Sautee this for about 5 - 10 minutes, stirring occasionally. Remove from skillet and set aside.
Heat the other half of the butter in the skillet. Add the skirt steak to the pan. Season with salt and pepper. Cook the steak on both sides for about 2 - 4 minutes.
Once the steak is cooked to your standards, add the onion and bell peppers to the pan. Stir together well.
Add the shredded provolone cheese to the skillet. Put a lid over the skillet and let cook until cheese starts to melt.
Place the lettuce leaves on a plate and spoon the steak mixture on each lettuce leaf. Garnish with parsley. Enjoy!
Notes
This makes a total of 4 servings of Keto Philly Cheesesteak Lettuce Cups. Each serving comes out to be 499 calories, 36.4g fat, 3.8g net carbs, and 36.9g protein.