Directions

1. To make the butter, tip all the ingredients into a bowl and season generously with pepper and a little salt. Beat until completely combined then tip onto a sheet of cling film and roll into a log. Refrigerate until hard. Can be made up to 3 days in advance or frozen for up to 1 month.
2. One breast at a time, lay them smooth-side down and remove the mini fillet. Make an incision down the middle of the fillet half way into it to make a pocket; it is essential that you don't cut all the way through the meat. Lay a piece of cling film over the breast and, using a meat mallet or rolling pin, flatten it out slightly. On another part of the board bat out the mini fillet slightly.
3. Divide the butter into four and squash into flattish discs. Stuff each of the pockets that you made with a disc of butter. Cover each with the mini fillet and fold the sides of the breast over it. Set aside.
4. Tip the flour, eggs and breadcrumbs into separate shallow containers. Working methodically, completely coat each breast in flour, then egg, then breadcrumbs, then dip back into the egg and finally again in the breadcrumbs. Set aside. The chicken can be prepared the day before and left in the fridge or frozen for up to 1 month - defrost completely before cooking.
5. To cook, heat oven to 200C/fan 180C/gas 6. Heat a decent layer of oil in a large frying pan and, once hot, turn the heat down to medium. Fry the Kievs for 2-3 mins on each side until dark golden. Lift them onto kitchen paper to absorb any excess oil then transfer to a roasting tin. Cook in the oven for 20 mins or until the Kievs feels firm when prodded at the widest part. Serve immediately with the lemon wedges and watercress, plus your favourite retro side dish - Russian salad is good.