1 lb Sorrel
3 oz Butter
Large onion, chopped
2 tb Flour (heaped)
2 1/2 l  Stock
2 tb Breadcrumbs
Salt and pepper
2    Egg yolks
150 ml Cream

Wash the sorrel well and chop it up. Heat the butter in a saucepan and
just soften the sorrel and onion in it. Shake the flour over the
vegetables and mix well. Let it cook for about 1 minute. Meanwhile bring
the stock to the boil, then add to the pan. Add the breadcrumbs, season to
taste, and bring to the boil, then simmer for about 1 hour covered. (It can
be liquidized at this point, but neednt be.) Beat the egg yolks with the
cream and add a little of the hot soup to the mixture, stirring well; then
add gradually to the soup pot, stirring well, over the heat, but being
careful not to let it boil.