Season steak pieces with garlic powder, smoked paprika, salt, and pepper. Let sit for 5 minutes.
Cook tortellini in boiling salted water until al dente (about 3-5 minutes for fresh). Drain, reserving 1/4 cup pasta water, and set aside.
Heat olive oil in a large skillet over medium-high heat. Sear steak for 2-3 minutes per side until golden. Remove and rest.
In the same skillet, melt butter and sauté minced garlic for 1 minute until fragrant.
Stir in heavy cream and milk; simmer gently for 2 minutes. Gradually whisk in Parmesan until smooth and thickened. Add reserved pasta water if needed for consistency.
Add cooked tortellini and steak to the sauce. Toss to coat evenly. Heat through for 1-2 minutes.
Garnish with parsley, extra Parmesan, and cracked pepper. Serve immediately.