Separate the eggs yolks from the egg whites. Save the egg whites for another use.
Mix sugar, cornstarch, flour, salt & hot water in sauce pan and heat to boiling, stirring constantly.
When it begins to boil, continue cooking (and stirring!) for 2 minutes. It will thicken as it continues to cook and you stir
After two minutes, add a ladle of the hot mixture to the egg yolks, to warm the eggs, stirring again - then add all of the egg yolk mixture to the hot sauce pan.
Add the lemon, zest & butter. Reduce heat to low & continue stirring & cooking for another two minutes.
Place in pretty bowls for serving. Right before serving, top with a dollop of whipped cream & garnish with some lemon zest. Beautiful!