Preheat the oven to 190C/375F/Gas 5.
Melt the butter in a small saucepan. Add the onions and cook them for about 6 minutes or until they are transparent. Add the herbs, breadcrumbs and seasoning, stirring well to combine everything.
Spoon the stuffing into the cavities of the apples. Place the apples into a dish, dot the top with butter and put into the oven for about 45-60 minutes. Serve as an accompaniment with pork or duck dishes.