We prefer chicken to steak fajitas in our house, but I'm sure it would taste great with beef as well. I ALWAYS marinate boneless, skinless breasts OVERNIGHT, grill, and slice thinly. I also use half the marinade for sliced onions and peppers, which I marinate in a seperate ziplok bag, then saute in a hot skillet. If serving buffet style, I lower the flame in the skillet, add a little of the veggie marinade, and the sliced, grilled chicken to the skillet. That way, nothing gets cold or dried out.