Leave ribeye roast 45 minutes to 1 hour in the freezer to make it easier to slice;
Preheat your grill to high heat, between 400 and 450°F, with your grilling stone inside;
Cut whole ribeye roast across the grain into ⅛ thick slices, or as thin as you can.
Season the meat with garlic salt and ground black pepper to taste;
Sauté the onions on your grilling stone with olive oil until golden brown.
Move onions toward the edge of the stone to make room for the beef and spread the meat evenly across the stone.
Add a handful of wood chips onto hot coals and close the lid; cook 4 to 6 minutes;
Combine grilled meat and onions and continue to cook until the desired doneness.
Divide into 3 to 4 servings then place slices of provolone cheese on top of each portion.
Close the lid and wait 30 seconds for the cheese to melt.
With a barbecue spatula, carefully transfer each meat and onion servings into a hoagie roll.