Onion Baked Chicken

Preheat an oven to 425 degrees F (220 degrees C). Combine the soup mix and panko in a mixing bowl; set aside. Line a baking sheet with foil.
Coat the chicken breasts all over with mayonnaise, then press into the panko mixture. Place the breasts on the baking sheet.
Cook the chicken breasts until no longer pink in the center and the juices run clear, about 25 minutes. An instant-read thermometer inserted into the center should read at least 165 degrees F (74 degrees C).