Simmer the stock, coder & rice in a covered pot with salt, pepper & lemon rind for 40 minutes. Puree & return to the pot. Mix in the lemon juice & simmer gently. Cool & skim any fat that might appear on the surface. Chill. To serve, scatter with the chives & garnish each bowl with a slice of lemon. Adapted from Pamela Westland, "Fruit"