The truth is that a range of sizes will work for the chicken door. The door should be at least 8 inches wide and up to 12 inches tall. My recommendation comes from experience building a coop and the book Poultry House Construction.
Pan-fry a T-bone steak quickly over high heat. Heat the pan on the stove top on high, then place the steak in the center of the pan. This sears one side of the steak almost immediately. Turn the steak after 6 to 8 minutes using tongs so you don't puncture the meat and let the juices escape. Let the steak fry for another 6 to 8 minutes.
You can sear the steak on high heat, but move the meat to a cooler part of the grill to finish it. If using a gas grill, turn the heat on high for preheating, and then turn it down to medium a minute before putting the meat on. By the time the meat is seared, the temperature will adjust. Use a timer or your watch. Grill four to six minutes on one side. Flip the steak, and cook for another four to six minutes on the other side. The length of cooking time will vary according to how thick your steak is and how well-done you want it. Steak must be cooked to at least 145 degrees in order to be eaten safely.