The reverse sear method slow-cooks steak in an oven then sears it at high heat on a hot pan. It guarantees a perfectly cooked steak every time with a flavorful crust and beautiful pink center.
Bring the steak to room temperature for 30 minutes.
Preheat the oven to 225°F.
Generously season the steak with salt and pepper then insert a probe thermometer into the center. Place on a baking sheet lined with parchment paper or foil. Bake the steak until it reaches 115°F for medium rare.
Heat a large cast iron skillet on high heat and add 1 tablespoon of oil.
Sear all sides and edges of the steak for 1-2 minutes on each side.
Add butter and rosemary and baste the steak for 1-2 minutes.
Slice into ¼" pieces. Season with salt and pepper and drizzle the butter from the pan on top.
Notes
Use a high smoke point oil like vegetable or avocado oil.
Cooking time is an estimate and will depend on the size of the steak and desired donesness.
Adjust the bake time based on how you like your steak.