In a small bowl, combine the chili powder, salt, oregano, cumin, garlic powder, black pepper, and mustard powder.

Set up your grill for direct grilling and preheat to high. Toss the mesquite chips on the coals or put them in your grills smoker box.

Season the steaks generously on both sides with the rub. Brush and oil the grill grate. Arrange the steak on the grate placing it on a diagonal to the bars. Grill for about 3 - 4 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 3 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.

Transfer the steaks to a warm platter or plate and keep warm.

Meanwhile, heat the olive oil almost to smoking in frying pan on the grills side burner. (If you dont have a side burner, do this on your kitchen stovetop.) 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.