A highly enriched pureed soup of fresh garden peas with mint and cream. (J.Salmon)

The original source of this receipt isn't known. Can you help? raise an issue on GitHub

Shropshire Pea Soup
2 oz butter
small onion, skinned and finely chopped
2 lb fresh peas, shelled
2 pints light stock
1/2 tsp sugar
2 large sprigs of fresh mint
salt and pepper
2 egg yolks
5 oz cream
sprig of mint to garnish