For a deeper smoky flavor, consider using mesquite wood chips when grilling. If you don't have time for a long marinade, even a 2-hour soak will impart noticeable flavor. Serve these kebabs with a side of cilantro-lime rice or a refreshing avocado crema. Feel free to substitute the beef tenderloin with sirloin or chicken thighs, adjusting the grilling time accordingly. Soaking the skewers prevents them from burning on the grill.