Cook pasta according to directions. When finished drain and set aside.

While pasta is cooking, preheat a large skillet to medium high. Add 2T. olive oil, sirloin tips, salt and red pepper flakes in a single layer in preheated skillet. Sauté for 3-4 minutes per side until steak is browned and cooked to desired doneness. Remove steak pieces from pan and set aside.

Turn pan down to medium. Add butter, garlic and 2 T. olive oil. Cook until butter is melted, and garlic is fragrant. Add pasta and parsley, stirring to coat. Remove pasta from pan to serving dish. Top with steak bites, Parmesan cheese and additional chopped parsley, if desired.