This is one of my favorite salads. I add more cilantro than is called for because I love it so much. Make a little extra dressing and keep it on hand in the fridge. Can be used for marinates, dips and of course salad dressing.
In a jar with a tight-fitting lid (a canning jar works best), combine the oil, lime juice, cilantro, cumin, salt and red pepper flakes. Do a dance and shake the jar well.
In a bowl, combine the lettuce, chicken and tomatoes. Drizzle with dressing and toss to coat. You can add extra cilantro if you wish on top. Refrigerate any excess dressing. I have also used some of this to marinate the chicken in a separate bowl or container prior to cooking. Turned out very well.