BVC Eats: Fresh green pea soup

I made this soup up out of my head after I read in a Georgette Heyer novel about a chef who, though he could of course prepare elegant French delicacies for his fashionable employer, knew also how to cater for an old lady with a sensitive digestion. He offered her a soup made with fresh green peas. (Can you name that Heyer novel and the old lady who enjoyed the soup?)

Fresh Green Pea Soup
serves four

12 to 16 oz fresh green peas, not canned or frozen
2 Tablespoon butter
½ cup sweet onion, minced
3 cups chicken stock
½ yam or sweet potato, minced
¼ to ½ teaspoon salt
4 to 8 oz whipping cream or half-and-half

Cook the yam in 1 cup stock until mushy-soft. Strain out any skin or hard bits. Reserve stock. Allow to cool.

Sautee the minced onion in the butter until the onion is translucent. Optional: sautee 1 cup sliced butter lettuce, Bibb lettuce, or Boston lettuce until bright green and then rinse under cold water to keep the color bright. Allow to cool.

In a separate pot, boil 2 cups stock and add the peas. Cook until the peas are vibrant green and tender, about five minutes. Strain. Reserve stock. Run the peas under cold water to keep the color bright.

In a blender, blend all ingredients, except the garnishes, and including all the reserved stock, until smooth.

Chill.

Suggested garnishes:
chopped chives
garlic chives
mint
basil
other fresh spring herb
dash nutmeg
2 to 4 T sour cream
1/8 c whole fresh green peas

Serve cold with garnishes to your taste. Mint is more refreshing; sour cream, chives, or nutmeg are heartier.