To make the chicken: Heat oven to 450°F. Spray large cookie sheet with cooking spray or grease.
In large resealable food-storage plastic bag, place taco seasoning mix; Place chicken in bag; seal and shake to coat., marinate anywhere from 10 minutes to 24 hours (the more the better!).
In a medium bowl, beat egg. and set aside. Pour panko breadcrumbs in a large dish. Dip chicken into egg then into the panko crumbs, then Place chicken on cookie sheet. Repeat until all the chicken tenders are coated, Spray with cooking spray or lightly drizzle with oil.
Bake 15 to 20 minutes, turning once, until chicken is no longer pink in center and bread crumbs are golden brown. Serve with creamy avocado dip or sour cream.
To make the avocado dip:
In a food processor, combine avocados, sour cream, cilantro, lime juice, jalapeno, and salt. Pulse until smooth, scraping down sides as necessary. Serve with chicken tenders.
Avocado dip adapted from Martha Stewart