In bottom of double boiler, bring about 2” of water to the simmer point (around 200°F). Maintain the water at this simmer point over medium-low heat. Place sugar in top of double boiler or heat-proof bowl. Mix in the clementine zest. Whisk the clementine juice into sugar.

In small bowl, lightly beat the 2 egg yolks and the whole egg together with a fork, just enough to break up the yolks and blend with the whole egg. Whisk the eggs into the sugar-clementine juice mixture. Add the soft butter. Place this pot or bowl over the simmering water. Stir the mixture continuously as it cooks until it is thickened and the temperature of the mixture registers 170°F on a candy thermometer. Be patient as this will take awhile. Make sure the water in the bottom of the boiler does not boil and stays only at the simmer point.

Remove curd from heat and strain through a mesh strainer to remove any of the egg white that may have coagulated as well as the clementine rind. Pour strained curd into a sterilized bottle. Place a piece of plastic wrap directly on the surface of the curd to prevent it from forming a skin on top. Cool at room temperature. Remove plastic wrap. Cover jar tightly and refrigerate for up to 1 week. Yield: Apx. 1 cup