For the parsley and chive butter, mix the butter, parsley and chives together in a mixing bowl then spoon onto a sheet of clingfilm or greaseproof paper.
Roll into a log, twisting the ends to secure, then place into the fridge for one hour to harden.
For the chicken, butterfly the chicken breasts by cutting almost in half lengthways, open the breast out and flatten with the palm of your hand.
Blend the peanuts to a powder in a food processor and mix with the breadcrumbs.
Place the flour and beaten egg into separate bowls and season each with salt and freshly ground black pepper. Dredge the chicken in the flour, then dip into the egg mixture and roll in the peanut breadcrumbs.
Heat the butter and olive oil in a large frying pan. Add the chicken breasts, one at a time, and fry for 2-3 minutes on each side, or until golden-brown. Test the chicken breast is cooked by inserting a skewer into the thickest part of the meat. If the juices run clear, the chicken is cooked. Remove the chicken from the pan and set aside to drain on kitchen paper.
For the mash, cook the potatoes in boiling water for 12-15 minutes, or until the potatoes are tender.
Drain the potatoes and return to the pan. Place over a low heat for one minute to drive off any excess moisture.
Mash the potatoes well or pass through a ricer into a clean saucepan.
Meanwhile, place the butter and milk into a saucepan and bring to a simmer then beat into the mashed potato. Season, to taste, with salt and freshly ground black pepper.
To serve, melt the butter in a frying pan until just foaming, then add the spinach and cook until just wilted. Season with a little salt, black pepper and nutmeg.
Spoon the mash onto serving plates, top with the chicken and spoon the spinach alongside. Cut several slices of butter and place on top of the chicken breast.