Boil a large pot of salted water over high heat. Add medium shell pasta and cook according to package instructions until al dente, about 8-10 minutes. Reserve ½ cup of pasta water before draining.

In a large skillet, heat olive oil over medium-high heat. Add sliced steak, cooking for 2-3 minutes per side until browned. Remove from pan and set aside.

Reduce heat to medium, add butter with diced onion and minced garlic to skillet. Sauté for 3-4 minutes until onion is soft and fragrant.

Sprinkle in smoked paprika and de-glaze with beef broth or white wine, scraping brown bits. Pour in heavy cream and grated Parmesan, stir until smooth and simmer for 3 minutes.

Add cooked pasta and seared steak back to the skillet, tossing to coat everything in the sauce. Add reserved pasta water if the sauce seems too thick.

Season with salt and black pepper. Garnish with fresh herbs if desired, then serve hot.