Place the chicken in a medium-size bowl. Drizzle with 1 tsp of oil. Sprinkle with Mexican Seasoning.
Heat a large skillet over medium-high heat. Add 1 tsp oil to the skillet. Add the chicken and toss to coat. Cook for 3- 4 minutes, constantly stirring, until the chicken has browned and is cooked through. Transfer the cooked chicken to a plate and tent with foil to keep warm.
Add the squash, pepper, corn, and garlic to the empty skillet. Sprinkle with salt and pepper. Continue cooking over medium-high heat, stirring frequently, until the zucchini and the peppers wilt just slightly and everything is warm, about 4 minutes.
Add the chicken back to the skillet. Add the lime juice and scrape all the browned bits off the bottom of the skillet, stirring and mixing the juices over the chicken and vegetables. Remove from the heat. Sprinkle cilantro and Cotija over the skillet, if desired.
MAKE AHEAD DIRECTIONS:Store this in an airtight container for up to three days. Reheat on the stove, in the microwave, or covered in the oven.