Mix cold water, kosher salt, and honey in a large bowl; stir until salt dissolves. Add chicken breasts, and weigh them down with a plate to keep them completely submerged. Cover entire bowl with plastic wrap and refrigerate for 1 hour.
Remove bowl from refrigerator; drain and dry chicken. Pour buttermilk over chicken in a large bowl. Set aside at room temperature for 15 minutes.
Combine flour, black pepper, garlic salt, onion salt, and cayenne pepper in a large bowl.
Coat each chicken breast in flour mixture until well covered on all sides; place flour-coated chicken breasts on a cooling rack to dry for 15 minutes.
Heat vegetable oil in a large skillet to 350 degrees F (175 degrees C). Cook chicken breasts until browned and no longer pink in the center, about 10 to 15 minutes. An instant-read thermometer inserted into the center should read at least 165 degrees F (74 degrees C).
Transfer chicken to a cooling rack; allow to cool for 5 minutes.
