Line a large cutting board with plastic wrap or parchment paper. Lay chicken breasts on top in a single layer, and then cover with another piece of plastic wrap or parchment paper.
Using a meat mallet or a heavy skillet (cast iron works best), pound each chicken breast to about 1/2-inch thickness.
Transfer the chicken to a large bowl or zip-top storage bag. Add all remaining ingredients for the marinade.
Cover and refrigerate for 30 minutes.
Working in 2 batches, heat 1 teaspoon olive oil in a large skillet over medium-high heat.
Remove chicken from marinade and shake off any excess. Transfer to hot skillet and cook for 6-8 minutes on both sides, or until the internal temperature reaches 165F and is fully cooked.
Add the remaining 1 teaspoon of olive oil and repeat the same steps with the remaining 2 chicken breasts.
Transfer chicken to a cutting board and let rest for 5 minutes. Slice and serve in salad when ready.
To make the cilantro-lime dressing
Add all dressing ingredients to a blender or food processor. Blend until smooth.
To assemble the salad
Place the chopped romaine lettuce in salad bowls and top with cherry tomatoes, beans, corn, red onion and sliced chicken.
Drizzle with cilantro-lime dressing and serve.
Notes
To store, keep the leftovers in an airtight container for up to 4 days in the fridge.
For the best flavor, leave the chicken to marinate anywhere from 30 minutes to 8 hours. It shouldn’t be left any longer or else the acid will start to affect the texture of the meat.
Want to make a vegan southwest salad? Replace the chicken with a plant-based alternative, chickpeas, or roasted sweet potatoes instead.