Preheat the oven to 425F.

Line a large baking sheet with parchment paper.

Combine the panko, Parmesan, dried parsley, and salt in a shallow dish.

In a separate shallow dish, mix together the mayonnaise and mustard.

Dredge each chicken breast in the mustard mixture, then coat with the panko mixture. Transfer the chicken breast to the prepared baking sheet. Repeat with the remaining chicken breasts.

Bake chicken on middle rack of oven for 7 minutes.

Carefully flip each chicken breast. Continue baking until the thickest part of the chicken breasts reaches an internal temperature of 165°F, about 7 minutes.

Check to see that chicken is done. Remove from oven or add time as needed.

Allow the chicken to rest for 5 minutes before serving.