Creating Italian Stuffed Flank Steak is straightforward if you follow these steps:

1. Preheat Oven: Preheat your oven to 375°F (190°C).
2. Prepare the Steak: Place the flank steak on a cutting board. Use a sharp knife to slice it horizontally, creating a pocket but not cutting all the way through.
3. Make Filling: In a bowl, combine the ricotta cheese, spinach, Parmesan cheese, mozzarella cheese, minced garlic, oregano, basil, red pepper flakes, salt, and pepper. Mix well until combined.
4. Stuff the Steak: Spoon the filling into the pocket of the flank steak, spreading it evenly.
5. Roll and Tie: Carefully roll the steak, starting from one end, and secure it with kitchen twine. Tie it tightly to hold the filling inside.
6. Season the Steak: Drizzle the rolled steak with olive oil and season generously with salt and pepper.
7. Sear the Steak: Heat a large oven-safe skillet over medium-high heat. Sear the steak on all sides until browned, about 3-4 minutes per side.
8. Bake: Transfer the skillet to the preheated oven and bake for 25-30 minutes or until the internal temperature reaches 135°F (57°C) for medium-rare.
9. Rest the Steak: Remove from the oven and let the steak rest for 15 minutes before slicing.
10. Slice and Serve: Carefully remove the twine, slice the steak into rounds, and serve.

These steps will guide you in creating this incredible dish effortlessly.