Pat steaks dry with paper towels and place on a rimmed baking sheet.
Drizzle with olive oil.
Sprinkle with dry rub on both sides.
Peel onions Slice onions into 1/2 inch slices.
Mix butter with garlic, smoked paprika and pepper.
Spread the butter on one side the onion slices and stack back together.
Wrap tightly with heavy duty aluminum foil.
Prepare a grill fire to 400° using hickory, oak or pecan for smoke flavor.
Place onion over indirect fire while the grill gets hot, with the grill closed. A medium sized onion should be cooked through in about 25- 30 minutes.
When onion has been cooking for about 20 minutes, add the steaks over direct fire.
Lower the grill temperature to about 350°. Cook the steaks with the grill closed 5 minutes.
Flip the steaks and continue to cook until desired temperature is reached, about another 3- 5 minutes for medium.
Remove steaks and onion from the grill. Let steaks rest 5 minutes before serving.
Carefully open the foil packet.
Serve steaks with grilled garlic butter onion slices.