1 baking potato or any large floury potato (about 300g/10陆oz), peeled and roughly chopped
small bunch fresh mint (about 5 sprigs)
1 large onion, roughly chopped
salt and black pepper
1 litre/1戮 pint stock from cooking the gammon (alternatively use vegetable or chicken stock)
1 tbsp butter or vegetable oil
100g/3陆oz cooked gammon or ham, shredded
500g/1lb 2oz frozen peas