The recipe said to marinate the whole steak in the top ingredients and then broil it, but I actually sliced it into thin strips first. I let the beef marinate over 8 hours (from morning until after work). I sauteed the onions and bell peppers in a hot skillet for about 4 minutes before adding the beef to the skillet and cooking it that way. I figured that when I get fajitas in a restaurant, they come on cast iron, so they should be cooked on the stove, not in the oven. I could be wrong about this.