Season the chicken with the chili powder, cumin, paprika, salt, and pepper, and marinate briefly in olive oil.
Grill or pan-sear the chicken until cooked through, then let rest and slice.
Whisk together olive oil, lime juice, minced garlic, salt, and pepper for the dressing.
In jars, layer the dressing at the bottom, followed by the sturdier ingredients (black beans, corn, tomatoes), then the sliced chicken and avocado, and finally the salad greens on top.
Sprinkle with red pepper flakes and cilantro.
Shake or toss well before eating.