In a small bowl mix together the butter, parsley and garlic with a good pinch of salt. Shape into a log then refrigerate for 20 minutes to firm up.
Make an incision into each chicken breast across the centre, making sure you don’t cut all the way through- you just want to make a pocket to fit the butter inside.
Once the butter has chilled, cut into rounds and stuff inside each breast, trying to enclose as neatly as possible. Dip each breast into a shallow bowl filled with the flour, then into another bowl filled with the egg, and finally into a third bowl filled with the breadcrumbs. Repeat the process again- this will make a double seal to ensure the butter doesn’t leak out when cooking and also make it extra crispy. Place in the fridge to chill for 30 minutes.
Preheat the oven to 160c
When ready to cook, heat a frying pan with a shallow layer of vegetable oil over a medium heat. Cook the kievs for a couple of minutes per side or until nicely golden all over before transferring to a baking tray and baking for 20 minutes. Serve right away.