Heat grill until coals are hot or until grill pan is almost smoking. For porterhouse steaks, grill 6 to 7 minutes per side for medium-rare; 7 to 9 minutes for medium. For rib eye or shell steaks, cook 5 to 6 minutes per side for medium-rare, 6 to 7 minutes for medium. Remove; squeeze a wedge of lemon on each steak.
To make the focaccia salsa, begin by ripping the bread into small pieces. Set aside. Heat olive oil in a large sauté pan over medium heat. Add shallots and cook 3 minutes, or until golden. Add garlic, bread, rosemary and parsley, then stir with a wooden spoon until mixture is evenly coated with olive oil and bread is golden brown, 6 to 8 minutes. Remove from heat and season with salt and pepper.
Presentation 1: Portable Porterhouse
Pass whole steaks around the table on a wooden cutting board with a bowl of salsa and remaining lemon wedges.
Presentation 2: Sit-Down Dinner
Slice steaks against the grain into 1/4-inch pieces. Overlap slices on a plate; make an S pattern on meat with 1/3 cup of salsa. Garnish with lemon wedges and parsley.