Cut each chicken breast in half lengthwise so you are left with 2 relatively equal pieces for each breast. Add lime juice to both sides of each piece and season each side with salt and pepper.
Heat the olive oil in a medium to large skillet over medium-high heat. Place the chicken in the skillet. You might need to work in batches. Cook the chicken on one side for about 5 minutes.
When you turn the pieces over, sprinkle some of the chipotle spice mix on the cooked side now facing up. Cook this side for about 5 minutes.
Turn the chicken pieces over again and follow the same process of adding chipotle spice mix to the chicken pieces.
As soon as you finish adding the lime juice and spice mix, turn the pieces over again for about 30 seconds just to sear the spice mix.
Set the pieces on a plate to rest while you build your salad.
Place some Romaine lettuce in a bowl or on a plate. Add some corn, black beans, tomatoes, red onions, and avocado on top of the lettuce.
Slice the chicken and place some on top. Dress with the Avocado Crema Dressing and fresh cilantro.
If desired, you can also add some queso fresco and sour cream.
Chipotle Spice Mix Recipe
Thoroughly mix all ingredients in a small bowl until they are complete blended. Store the unused portion in an airtight container for 6 months.
Avocado Crema Dressing
Combine all the ingredients in a small processor blender and blend until smooth, about 1 minute.