Preheat an oven to 400 degrees. Line a large baking sheet with a silicone baking mat or parchment paper. Cook and season the steak and mini peppers according to desired taste. Chopped the cooked steak into desired size pieces (I make my pieces bite size) Set aside
Place the flatbread in a single layer on the prepared baking sheet. Keep a little space between each flatbread for an even cook. Spread 2 TBS (or desired amount) of the sauce of choice over each one of the flatbreads. Cover the sauce with a layer (or desired amount) of shredded cheese.
Top the cheese with baby spinach, cooked steak, sweet peppers and any vegetables of choice. Sprinkle a light layer of more shredded cheese over the filling. Place the flatbreads in the preheated oven. Bake at 400 degrees for 3 to 5 minutes or until the cheese is melted.
Remove the cheesesteaks from the oven. Let site 3 to 5 minutes to avoid burning fingers. Serve flatbreads open face or fold flatbread over filling before eating.