I lifted this from an article;
How to Make Black and Blue Steak
The hardest part about making it is ensuring there are plenty of flames rising high above the grates on your grill. Let me be the first to say that a Pittsburgh style steak must be done on an open flame grill, it cannot be done on a pan on your cooktop because it will take way too long to char on the outside without it being rare in the middle. So, the first thing you can do is crank your grill up to the hottest setting it can go and let it hold that temperature for about 7 to 10 minutes before cooking.
When using cuts of meat like a New York strip or a ribeye, it’s actually easier to achieve a Pittsburgh style steak because you can simply fabricate your cuts of beef when you are breaking it down to keep some more of the fat on. When it comes time to cook the steak you trim a bit more of the fat off and then you place that fat around the outside of the steak. Or when fabricating simply trim all the fat and set it to the side in a freezer or on a ready to order basis. Meat fat breaks down pretty slow but drips profusely causing lots of flame and fire which will help you achieve that char to your meat. THIS is the best way to make a Pittsburgh style steak.