Step 1: Soak 1 cup mesquite chips or chunks in water to cover for 1 hour, then drain.
Step 2: Set up the grill for direct grilling and preheat to high. Toss the mesquite chips on the coals.
Step 3: Season the steaks generously on both sides with salt and pepper. Brush and oil the grill grate. Arrange the steak on the grate placing it on a diagonal to the bars. Grill for about 2 minutes, then rotate the steak a quarter turn to create an attractive crosshatch of grill marks; grill for 1 to 2 minutes more. Turn the steak over and grill for about 2 minutes, then rotate a quarter turn and finish cooking to the desired doneness. The internal temperature when read on an instant read meat thermometer should be 140 to 145 degrees F for medium-rare.
Step 4: Transfer the steaks to a warm platter or plate and keep warm.
Step 5: Meanwhile, heat the olive oil almost to smoking in frying pan on the grill’s side burner. Add the jalapenos, garlic, and cilantro and cook until fragrant and just beginning to brown, 2 minutes. Spoon this mixture over the steaks and serve at once.