Bring a large pot of salted water to a rolling boil. Add the tortellini and cook per package directions until al dente. Before draining, scoop out and reserve 1 cup of pasta water. Drain the tortellini and set aside.

Pat the steak dry with paper towels. Season both sides generously with salt, black pepper, garlic powder, and smoked paprika.

Heat 2 tablespoons of olive oil in a heavy skillet over medium-high heat until shimmering. Add the steak and sear without moving for 3 to 5 minutes per side, depending on thickness and desired doneness.

Transfer the steak to a cutting board and let it rest for 5 to 10 minutes. Slice thinly against the grain.

Reduce the skillet heat to medium. Add 4 tablespoons of butter to the pan and let it melt. Add the minced garlic and sauté for 30 to 45 seconds until fragrant—do not brown the garlic.

Pour in the heavy cream and whole milk. Stir and bring to a gentle simmer. Gradually add the grated Parmesan, stirring until the sauce becomes smooth and glossy.

If the sauce feels too thick, stir in reserved pasta water a little at a time until you reach the desired consistency.

Add the drained tortellini and sliced steak to the skillet. Gently toss or fold for 1 to 2 minutes until everything is warmed and coated in the sauce.

Finish with chopped parsley, a pinch of red pepper flakes if you like heat, and a crack of black pepper. Serve immediately.