Bring a large pot of salted water to a boil and cook the cheese tortellini according to package directions.
Drain the tortellini and reserve a small cup of pasta water for loosening the sauce if needed.
Pat the steak dry, cut it into bite-size pieces, and season with salt, black pepper, garlic powder, and smoked paprika.
Heat olive oil in a large skillet and sear the steak pieces until browned, then move them to a plate.
Lower the heat, melt the butter in the same skillet, and cook the minced garlic until fragrant.
Stir in the heavy cream and whole milk, scraping up the browned bits from the bottom of the skillet.
Add the parmesan gradually and stir until the sauce is smooth, creamy, and lightly thickened.
Fold in the cooked tortellini, adding a splash of reserved pasta water only if the sauce is too thick.
Return the steak and juices to the skillet, toss gently, and finish with parsley, red pepper flakes, or cracked black pepper.