4 large egg yolks
3/4 c sugar
4 T unsalted butter, softened
Juice of 2 large lemons
2 tsp grated lemon zest
In large sauce pan, beat egg yolks and sugar until well combined. Add softened butter and lemon juice.
Cook over low heat, stirring constantly. Do not allow to boil. When the consistency is thick, remove from heat and add lemon zest. Place in airtight container and set in refrigerator to chill.
2 c heavy cream (not ultra-pasteurized)
Preheat your oven to 180F. Pour the cream into a shallow glass baking dish. (The cream should only come up the sides about 1-2 inches. Place in the oven for 12 hours, uncovered.
After heating for 12 hours, the cream will develop a skin. Carefully remove from the oven and let cool to room temperature. Once it has cooled, cover and refrigerate for 8 hours
Chill thoroughly. Gently skim the layer of clotted cream from the surface and place in a container. Gently stir till smooth. Store in the refrigerator for up to a week.