Cook the Pasta: Bring a large pot of salted water to a rolling boil. Add rigatoni and cook for 10-12 minutes until al dente. Drain and rinse under cold water.

Sear the Steak: Heat olive oil in a skillet over medium-high heat. Add steak pieces and sear until browned, about 3-4 minutes. Remove and rest.

Sauté the Vegetables: Lower the heat and add diced onion and bell pepper. Sauté for 5 minutes, then stir in minced garlic and cook for another minute.

Prepare the Sauce: Pour in the heavy cream, scraping the skillet to deglaze. Simmer for 2-3 minutes until slightly thickened.

Combine Cheese and Seasoning: Stir in crumbled blue cheese, oregano, salt, and black pepper. Cook until the cheese melts into the sauce.

Mix in Pasta and Steak: Return seared steak and drained rigatoni to the skillet. Fold gently to coat everything in the sauce.

Transfer to Baking Dish: Preheat oven to 375°F. Grease a baking dish and transfer the pasta mixture, then top with mozzarella cheese.

Bake to Perfection: Bake for 15-20 minutes until cheese is melted and bubbly.

Garnish and Serve: Let sit for a few minutes. Garnish with chopped parsley before serving.