Choose a porterhouse, T-bone, on sir loin steak, 1 1/2 inches thick.
Slash fatty edge at intervals don't cut into meat.
Place steak on broiler rack; broil top side, season with salt and pepper.
Turn, broil other side till brown and meat is done the way you like it.
Allow 15 to 20 minutes total for rare; 20 to 30 minutes for medium.
Place steak on seasoned plank.
Pipe border of Duchess Potatoes around meat, using pastry tube.
Broil potatoes with meat last few minutes.
(Or, bake in hot oven (450Â°) about 12 minutes.) Remove from broiler (or oven); add hot buttered vegetables (your choice) and pars ley.
Top steak with a pat or two of butter.
Place plank on serving tray.