In a large pot, bring salted water to a boil. Add the tortellini and cook according to package instructions, usually about 3-5 minutes. They should be al dente. Drain and set aside, reserving a bit of the pasta water.

In a large skillet over medium-high heat, melt 2 tablespoons of butter. Season steak bites with salt and pepper and add them to the hot skillet in a single layer. Sear for about 3-4 minutes until browned and cooked to your preference (medium-rare is about 130°F).

Once the steak is cooked, remove it from the skillet and set aside. In the same skillet, melt the remaining butter, adding the minced garlic. Sauté for 1-2 minutes until fragrant but not browned.

Pour in the heavy cream, stirring to combine. Let it simmer for 1-2 minutes, then stir in the grated parmesan cheese until creamy. If the sauce is too thick, add a splash of the reserved pasta water.

Add the tortellini and steak bites back into the skillet, tossing everything in the sauce until well-coated and heated through. Serve hot and garnish with fresh parsley.