Bring a large pot of salted water to a boil. Cook the rigatoni until al dente, according to package directions. Drain and set aside.

Heat olive oil or butter in a large skillet over medium-high heat.

Add the shaved steak and season with salt, pepper, onion powder, smoked paprika, and oregano. Cook for 3–4 minutes, until browned.

Remove the steak from the skillet and set aside.

In the same pan, add the onion and bell pepper. Sauté for 4–5 minutes until softened and lightly caramelized.

Add the garlic and cook for 30 seconds, until fragrant.

Return the steak to the pan, pour in the Worcestershire sauce, and toss to combine.

Sprinkle the shredded cheese over the mixture, cover, and let melt for 1–2 minutes. Remove from heat.

In a large saucepan, melt butter over medium heat.

Whisk in the flour and cook for 1–2 minutes, until smooth and slightly golden.

Slowly pour in the warm milk, whisking constantly to prevent lumps.

Continue whisking until thickened, about 8–10 minutes.

Season with salt, pepper, cinnamon, and nutmeg (if using). Remove from heat and stir in Parmesan cheese.

Reserve 1½ cups of the béchamel sauce.

Toss the cooked rigatoni with the remaining béchamel until evenly coated.

Spread half of the pasta mixture into the prepared baking dish.

Spoon the cheesesteak filling evenly over the pasta layer.

Add the remaining pasta on top, then pour over the reserved béchamel, spreading to cover the surface.

Sprinkle with shredded provolone or your cheese of choice.

Bake uncovered for 20–25 minutes, until golden and bubbly.

For a deeper golden crust, broil for 1–2 minutes at the end, watching closely.

Let the bake rest for 5–10 minutes before slicing. Garnish with chopped parsley and serve warm.