For an appropriately cooked medium strip steak, use an estimated cooking time to plan out meal prep, but don't rely on it solely to determine doneness. Cooking time varies by the meat's thickness, especially in the oven, where performance differs from stove to stove. For the best results, pan-sear the steak first, cutting down on baking time.
Computing Cooking Time
First, there's the matter of your steak's thickness. New York strip steaks typically come in around 1 1/2 inches thick, and they're not on the bone. Oven temperature affects cooking time, too; in general, use about 350 degrees Fahrenheit for steak. With these parameters, expect your strip steak to take approximately 16 minutes baking time to hit medium. To crisp and brown the exterior, pan-sear the steak for about 2 minutes per side first. This faster-cooking direct heat should shave at least 5 or 6 minutes off the oven time.
The internal temperature of your strip steak is the most accurate way to know when it's cooked to medium. Use an instant-read meat thermometer, inserting the tip of the stem into the center of the thickest part of the steak. It's at medium doneness -- and the temperature recommended by the U.S. Department of Agriculture for safety -- when it hits 145 F.