Preheat your grill or grill pan. I used a George Foreman Grill because it was convenient, but you could do this on an outdoor grill for extra flavor!
Liberally sprinkle the steak on both sides with salt and pepper, then put on the grill for about 7 minutes (depending on your cut/thickness). For maximum tenderness, don't overcook! When your steak is done, let it rest on a cutting board to allow the juices to redistribute. The salad is best served chilled, so don't worry about it getting cold!
While the steak is cooking/resting, chop the rest of the salad ingredients (except for the lettuce) and toss them in a bowl. For this recipe, a smaller dice/chop is preferred.
In a mason jar or other shaker, combine the dressing ingredients and give them a shake. Pour over your salad.
After the steak has rested, thinly slice it into small bites, then add it to the salad bowl. Mix thoroughly so the steak can absorb some of the dressing and tenderize even further.
Refrigerate until chilled. The great thing about this for a party is you can do all the work ahead of time!
Just before serving, chop your butter lettuce and add it to the salad bowl, mixing thoroughly. (If you add the lettuce sooner, it will wilt with the dressing.)