Preheat oven to 350°F (175°C). Line a baking sheet with parchment paper.

In a microwave-safe bowl, combine cream cheese and mozzarella cheese. Microwave in 30-second intervals, stirring in between, until completely melted and smooth.

Add eggs to the melted cheese mixture and mix well until fully incorporated. Add almond flour, baking powder, and garlic powder (if using). Mix until a dough forms.

Lightly flour hands with almond flour. Knead the dough for a couple of minutes until smooth and pliable.

Divide the dough into 4 equal portions. Roll each portion into a log shape, about 6-8 inches long. Place the rolls on the prepared baking sheet.

Bake for 20-25 minutes, or until golden brown and firm to the touch. Let the rolls cool slightly before slicing.

If steak isn't already thinly sliced, partially freeze it for about 30 minutes to make it easier to slice.

Heat olive oil or avocado oil in a large skillet over medium-high heat. Add sliced onions and bell peppers (and mushrooms, if using) and cook until softened and slightly caramelized, about 8-10 minutes. Season with salt, pepper, garlic powder, and onion powder to taste. Remove the veggies from the skillet and set aside.

Add the thinly sliced steak to the same skillet (you might need to do this in batches to avoid overcrowding). Cook the steak quickly, stirring frequently, until it's browned and cooked through, about 3-5 minutes. Season with salt, pepper, garlic powder, and onion powder to taste.

Return the cooked veggies to the skillet with the steak. Stir everything together. Arrange the provolone cheese slices on top of the steak and veggie mixture.

Cover the skillet and let the cheese melt, about 1-2 minutes. Alternatively, pop the skillet under the broiler for a minute or two to melt the cheese, watching closely so it doesn't burn.

Carefully slice each keto roll lengthwise, creating a pocket for the filling.

Spoon the Philly cheesesteak filling into each roll, packing it in nicely.

Serve immediately with your favorite keto-friendly toppings.