Fry garlic clove in olive oil & add ½ tin of anchovies. Stir until melted, adding more oil if too dry. Stir in cooked chopped chard until coated in the sauce. Season with black pepper.
Wash chard & cook covered for 5 minutes (the water clinging to the leaves should be enough). Drain and chop finely.
Bring stock to the boil, add Chard and simmer for 5 minutes.
Beat egg yolk with the cream and grated cheese. Remove soup from the heat, beat 4 fl oz of hot soup into the egg yolk and cream mixture then stir back into the soup. Add the nutmeg and seasoning. Heat gently to just below simmering point. Do not boil or the soup will curdle.