Bring a large pot of salted water to a rolling boil. Add the rigatoni and cook for 10-12 minutes until al dente. Drain and set aside.

In a large skillet, heat olive oil over medium-high heat. Add steak pieces and sear for 3-4 minutes until golden-brown. Remove steak and let rest.

In the same skillet, add more olive oil if necessary, diced onion, and bell pepper. Sauté for about 5 minutes until onion is translucent.

Reduce heat to low, add minced garlic, and cook for 1 minute. Pour in heavy cream, scraping up browned bits from the skillet.

Stir in crumbled blue cheese, dried oregano, salt, and black pepper. Cook over low heat, stirring until cheese melts and sauce thickens.

Return sliced steak to skillet and fold in cooked rigatoni with the sauce, ensuring even coating.

Transfer mixture to a greased baking dish and top with shredded mozzarella cheese.

Preheat oven to 375°F (190°C) and bake for 15-20 minutes until cheese is bubbling and golden.

Remove from oven, let sit for a few minutes, then garnish with chopped parsley and serve hot.