Steak overcooked: Did not account for carryover. Pull at 125°F, sauce adds 5–7°F. Sauce too thin: Simmer 2 extra minutes before cream. Ensure 36%+ cream. Grainy Parmesan: Pre-shredded, used or added to simmering sauce. Always block Parmesan, always off heat. No cast iron: Use the heaviest stainless skillet available; nonstick cannot handle the heat needed for a proper steak sear.