Preheat oven to 400° while thawing the puff pastry according to the package instructions.
2 sheets Puff Pastry
In a large skillet, heat olive oil over high heat. Once hot, add the peppers and onions. Season with seasoned salt and stir to distribute. Lower the heat to medium high and cook the veggies until soft and lightly browned, about 10-12 minutes. Set aside and return the pan to the heat.
2 tablespoons Olive Oil, 2 Green Bell Peppers, 1 Yellow Onion, Seasoned Salt
Add another teaspoon of olive oil and turn the heat to high. Once hot, add the shaved steak in an even layer. Season with seasoned salt and cook, undisturbed for 3 minutes. After 3 minutes, stir the steak to cook on the other side. Cook for another 3-4 minutes until the meat is no longer pink. Set aside.
1 lb Shaved Ribeye Steak, Seasoned Salt
Roll out both sheets of thawed puff pastry into a 10"x12" square. Add one sheet of puff pastry to a parchment lined baking sheet and spread on mayo and mustard, avoiding the outer inch on each side. Lay down 6 slices of cheese in an even layer, then top with the cooked veggies, then the steak. Finish with remaining cheese slices.
3 tablespoons Mayo, 2 tablespoons Dijon Mustard, 10 slices White American Cheese
Prepare your egg wash by scrambling an egg in a small bowl with a splash of water. Brush the egg wash on the outer rim of the puff pastry then top with the other sheet. Using a fork, press the two edges together to seal the pie. Egg wash the entire top of the tart then cut a few vent holes in the top. Finish the tart with a sprinkle of sesame seeds and flaky salt.
1 Egg, 1 tablespoon Sesame Seeds, pinch Flaky Salt
Bake in preheated oven for 25-30 minutes, rotating halfway, until the tart is deeply golden brown. Let rest for 10 minutes then slice and serve hot.