Put a quart of green peas into a saucepan with a slice of white onion,
cover with boiling water and cook until tender. Remove from the fire and
press through a puree sieve with the water in which they were boiled.
Return to the saucepan, set it back on the stove, let it come to a boil,
add a pint of rich milk, salt and white pepper to taste, a dash of
cayenne, and a large, generous tablespoonful of butter rubbed into an
even tablespoonful of flour, adding a little of the liquid before
stirring into the soup. Let it come to a boil, and add two
tablespoonfuls of whipped cream just as it is poured into the tureen.