How to Make It
Soak the mesquite chips in water for 30 minutes and drain. On a cutting board, sprinkle the garlic with a pinch of kosher salt and crush with the side of a knife until a smooth paste forms.
Lay the steaks in a large, shallow baking dish. Rub both sides of the steaks with the garlic paste. In a small bowl, combine the chile powder with 2 teaspoons of salt, the cumin, oregano and pepper. Sprinkle half of the rub on both sides of the steaks.
In another small bowl, combine the Tabasco with the Worcestershire sauce and spoon over the steaks; then pat the liquid into the spice rub so it forms a paste. Refrigerate the steaks for 30 minutes or for up to 4 hours.
Light a grill. Thread the onion slices onto skewers and brush with the olive oil, then sprinkle both sides with the remaining spice rub.
If using charcoal, scatter the wood chips over the coals. If using a gas grill, place the chips in the smoker box or on a 12-inch square of foil; fold the foil into a 6-inch square and poke 12 holes in the top. Place the package near the flames and heat until smoking. Lightly brush the grate with vegetable oil.
Set the steaks on the grill and cook over a medium-hot fire for 4 to 6 minutes per side for medium rare. Grill the onion slices until tender and nicely charred, 6 minutes per side. Transfer the steaks to plates and serve with the onion rings and lime wedges.