Blanch and finely chop almonds. Boil milk and almonds. Heat butter in a pan add, sauté onion until soft and transparent. Add flour, cook on low heat for a moment and add stock.
Bring to a boil and season with salt and white pepper powder. Add celery and simmer for fifteen minutes. Blend milk and almonds in a blender.
Strain boiling stock and combine with milk and almond paste. Reheat, adjust seasoning. Add egg yolks and cream and mix thoroughly. Take off the heat and chill.
Serve sprinkle with chopped parsley and a few peeled and pipped grapes.