Cap steak is a sirloin cut taken from the triangular muscle sitting right over the top sirloin cut near the back of the cow. It is a juicy, tender cut that doesn’t need much flavor added but does absorb flavors of marinades and dry rubs well before grilling or broiling. This cut does not have a lot of marbling but enough to keep it from drying out during cooking as long as the cooking process is quick. Some butcher shops call cap steak coulotte steak.
Trim excess fat from the edges of the steak.
Season the steak with salt and pepper or marinate in a blend of 2 tbsp. butter, 1/2 tsp. salt, 1/2 tsp. black pepper, 1/2 tsp. garlic powder and 1/2 tsp. soy sauce. Marinate in the refrigerator, removing the steak for at least one hour to warm to room temperature prior to grilling.
Preheat the grill on high heat on both sides. Close the lid while heating. Once heated, reduce one side to medium heat while keeping one side at high heat.
Sear the steak on the high-heat side of the grill for two minutes on each side. Searing cooks the outer layer of meat over high, direct heat to lock in juices. The surface of the steak will be browned.
Move the steak to the medium-heat side of the grill. Cook for another four to five minutes on each side for medium-rare steak. Medium-done steaks will cook for another six to seven minutes on each side, with well-done steaks cooking for eight to nine minutes on each side.
Let the steak rest for five minutes on a plate away from the heat to soak in all the juices released in the cooking process.
Preheat the oven on the broil setting. Twist aluminum foil into a 1-inch coil to keep the oven door ajar so the broiler doesn't turn off.
Season the cap steak with 2 tbsp. butter, sprinkling it with salt and pepper.
Place a drip pan on the bottom rack in the broiler. Place the steak on the next rack up, broiling it for five minutes. Turn the steak, broiling it for another five minutes.
Move the steak to the top rack in the oven, cooking it for three minutes before flipping it to cook for the last three minutes.
Remove the steak from the oven and set it on a plate. Cover it in foil for five minutes before serving.