Preheat the oven to 180°C / 350°F / Gas mark 4.
Line a baking tray with greaseproof paper and set aside.
In a food processor, blitz the bread to make breadcrumbs.
Season with salt and pepper and blitz once more.
Layer the breadcrumbs onto the baking tray and cook in the oven until just lightly browned, about 5 minutes, turning once.
Place all the garlic butter ingredients in a bowl and season well.
Mash with a fork until well combined, shape into two sausages, then tightly wrap and freeze until firm.
Can be made up to 3 days in advance.
When firm, slice each into 8 even pieces.
Lay a chicken breast on a chopping board and use a sharp knife to make a deep pocket inside the fillets.
Be careful not to cut all the way through.
Repeat with the remaining fillets.
Push 2 discs of butter inside each chicken breast, press to flatten and re-seal with your hands. Set aside.
Mix the breadcrumbs and parmesan on one plate, and tip the eggs onto another.
On a third plate, mix the flour with paprika and some salt.
Dip each breast in the flour, then the egg and finally the breadcrumbs, repeating so each Kiev has a double coating.
Chill for at least 1 hr before cooking, or freeze now.
To cook, preheat the oven to 180°C / 350°F / Gas mark 4.
Heat the oil in a large frying pan over a medium-high heat.
Fry the Kiev’s for 2-3 minutes each side until golden – you may need to do this in batches.
Transfer to a baking tray and cook for 20-25 minutes until cooked through