25g/1 oz butter
4 celery stalks, finely chopped
100g/4 oz fresh breadcrumbs
1/2 small onion, minced or cut very finely
Melt the butter in a pan and fry the celery until softened. Remove from the heat and mix in the remaining ingredients. Moisten with a little more melted butter if necessary.
Grease an ovenproof dish, spread evenly over and top with a few small knobs of butter and cook in a moderate oven for approximately 45 minutes.