Lemon Curd

I've actually never had lemon curd before, but I thought it would make a very nice addition to my tea party. I'm SO glad I made it, it was delicate, mildly sweet and perfect for my cream scones. I'm actually not certain how I've lived without it for so long. My guests ate it right up. And the great thing is, is it's easy to make and keeps well in the refrigerator for up to a week.
Ingredients
Source: Joy of Baking

3 large eggs
Juice of 3 lemons
1 tbsp lemon zest
3/4 cup sugar
4 tbsp. unsalted butter, diced and at room temperature

Directions
Whisk together eggs, lemon juice and sugar in a bowl over a double boiler. Cook, stirring constantly, until the mixture becomes thick and is the consistency of sour cream (160 degrees F), about 10 minutes. Remove from heat and pour through a fine meshed strainer into a medium bowl. Immediately whisk in butter until all of it is melted and incorporated into the sauce. Add zest and let cool. Serve immediately or pour into an air-tight container. If you decide to store the curd, make sure to put plastic wrap directly on the curd itself to prevent a skin from forming. Then cover with the lid of the container and refrigerate for up to a week. Makes 1 1/2 cups.