Cooking time: 30 mins
4 6- to 8-oz NY Strips, cut 1 to 2 inches thick
1 bunch rosemary, cut into eight 1-inch segments
2 cloves garlic, minced
4 tbsp butter
2 tbsp kosher salt
6 tbsp coarse ground black pepper
2 cups sliced portabella mushrooms
4 tbsp olive oil
1 cup beef broth
1 tbsp cornstarch
1 tbsp water
- Remove steaks and butter from refrigerator. Let stand while preparing next steps, until steaks have reached room temperature and butter is slightly softened. Mix the salt and pepper in a small bowl. Rub the steaks with the olive oil, salt, pepper, garlic salt, and fresh garlic.
- Preheat grill to 450°F with the lid closed.
- Place the steaks on the grill and place 1 rosemary sprig on top, saving the other 4 for garnish later. Let grill for 3 minutes, then remove rosemary and flip, allowing steaks to sear for another 3 minutes. Turn the steak 45 degrees and let cook for another 3 minutes, then flip and cook for another 3 minutes. Shorten grilling times for smaller steaks or to achieve your preferred level of doneness.
Remove the steaks from the grill and allow them to rest for between 5 to 8 minutes
- Test the temperature of the cast iron skillet with a few drops of water. When the water sizzles immediately, the cast iron is ready. Place the butter and mushrooms in the skillet and cook until mushrooms are tender. Add beef broth, stirring with a wooden spoon until all the browned bits in the bottom of the pan are dissolved. Mix cornstarch and very cold water in a bowl and whisk until smooth. Stir mixture into mushrooms, stirring frequently for another 2 minutes or until thickened and smooth.
Ladle the mushroom sauce over the steaks, and garnish each with the three remaining sprigs of rosemary and chives.