2 carrots (around 175g/6oz), peeled and diced
1 celery stick, thinly sliced
1 onion, finely chopped
chopped fresh flatleaf parsley, to serve (optional)
400g/14oz dried split peas
salt and freshly ground black pepper
½ tsp dried mixed herbs
1 tbsp sunflower oil
600–750g/1lb 5oz–1lb 10oz smoked gammon joint, string and any netting removed