Mix all of the ingredients for the marinade together and toss chicken in the mixture. Let it sit in the spices for at least 2 hours, up to 24.
Heat grill to medium-high. Remove chicken breasts from marinade and discard the spice mixture. If chicken breasts are very thick, place between pieces of waxed paper or plastic wrap and pound out to 1/2" - 3/4" thickness. Grill chicken breasts for 4 minutes each side. Remove from grill, cover loosely with foil and let rest for at least 10 minutes before slicing. If you choose NOT to pound the chicken out, you'll need to increase cooking time by a few minutes to ensure they are cooked through.
While chicken is cooking, place peppers and onions on the grill and cook for 3 minutes each side. Enough to soften and give some char to them, but not overcooked and mushy.
Cool chicken, peppers and onions completely before adding to salad.
Assemble
Place a couple of big handfuls of chopped romaine into your containers. Top with chicken, peppers, onion, corn, tomato. Use a cheese grater to grate your favorite cheese on top of your bowl and toss avocado chunks in a bit of lime juice before adding to the bowl.
Put the lids on, refrigerate and relax! Lunches are done!
Notes
Normally, I include a small wedge of lime to squeeze over this salad for a little extra zing.