Cut the chicken breast into two equal parts and then flatten them between two sheets of baking paper, using a meat mallet until they are and even 1 inch thick all over.
In a bowl, coat the chicken in the sour cream and refrigerate for at least an hour.
Pre-heat the oven to 180C(356F) fan-forced and line a baking tray.
Combine the bread crumbs, nuts and salt and pepper and spread onto a large plate.
Shake any excess sour cream from the chicken and one at a time, lay it on top of the crumb and press it in to coat it. Repeat on the other side and with the other fillet.
Heat a large fry pan over medium heat. Cook the chicken for 2-3 minutes a side until it just starts to turn golden.
Place the chicken on the lined oven tray and cook for 15 minutes or until cooked through.