Whisk marinade ingredients together in a large bowl, then add in the chicken breasts. Coat the chicken in the marinade, then cover and let it sit while you prep the rest of your salad.
Place a large skillet over medium-high heat. Add about a teaspoon of oil to the skillet, then add in the sliced onion and peppers. Cook the peppers and onions for about 3-5 minutes, or until cooked to your liking. Remove the peppers and onions from the skillet and set aside.
Return your skillet to medium-high heat, then add the chicken cutlets to the skillet. Cook chicken for about 5 minutes per side, or until a meat thermometer inserted into the chicken reads 165° Fahrenheit. Remove chicken from the skillet and let it rest on a cutting board for a few minutes before slicing.
Now, make the cilantro-lime dressing by adding all dressing ingredients to a small bowl and whisking together to combine.
Assemble the salad by placing the chopped lettuce, cherry tomatoes, cooked peppers and onions, cooked then sliced chicken, avocado, and pumpkin seeds to a large bowl. Drizzle the cilantro-lime dressing over the salad and toss to combine. Serve immediately or, meal prep this salad ahead of time by storing the dressing separately. Then, right before serving, pour dressing over the salad and enjoy!