Preheat the oven to 400 degrees F (200 degrees C).
Step 2
Pound chicken breasts with a meat mallet to an even 1/4-inch to 1/2-inch thickness. Season with salt and pepper on both sides.
Step 3
Pulse croutons in a food processor until finely crushed. Place crouton crumbs, flour, and beaten eggs into 3 separate shallow dishes.
Step 4
Dip each pounded chicken breast into flour, shaking off excess. Dip into eggs, letting any excess drip off, then press into crouton crumbs to coat.
Step 5
Heat olive oil in a large oven-proof skillet over medium heat. Fry chicken in hot oil for 2 minutes. Flip and fry for 2 more minutes. Remove from heat. Top each breast with 2 tablespoons giardiniera and 1 cheese slice.
Step 6
Cook in the preheated oven until chicken is no longer pink in the center and the juices run clear, 8 to 10 minutes. An instant-read thermometer inserted into the center should read at least 165 degrees F (74 degrees C). Top with parsley to serve.