Preheat the oven to 180℃.
Place the chicken breast onto baking paper, then cover with a few layers of cling film. Bash with a meat mallet or rolling pin until it is about 0.5 cm thick.
Spread the wholegrain mustard over the top, followed by the cheese, and finally the ham.
Roll it up like a swiss roll as tight as possible.
Coat the chicken in flour, then the egg and finally the breadcrumbs.
Heat a good amount of oil in a large frying pan, pan fry the chicken until the breadcrumbs are golden all over.
Transfer it to a baking tray and bake for 20 minutes.
Leave it to stand for a few minutes before cutting into portions.
Serve it hot or cold.
