Lemon Sauce is like a staple in our refrigerator! It's fantastic served over just about anything you can think of; toast, ice cream, gingerbread, angel food cake, pound cake, cheesecake, bread pudding.
Whisk three egg yolks in a liquid measuring cup. Set aside.
Add sugar and cornstarch to a saucepan. Whisk to combine.
Add salt and a little ground nutmeg. Nutmeg is optional but DELICIOUS!
Set saucepan over medium heat. While whisking gradually add water.
Continue whisking and cooking until the mixture begins to thicken. It should be about the constancy of thin gravy.
Slowly add about a small amount, about 1/4 a cup, of thickened lemon sauce to beaten egg yolks in the liquid measuring cup. Whisk.
While whisking lemon sauce in the pan, slowly add egg mixture to the lemon sauce and continue whisking until thickened. Drag the back of a wooden spoon or spatula through the lemon sauce. Once it leaves a trail behind it the sauce is the right consistency. The trail will close quickly but you should see a visible trail after dragging the spoon on the bottom of the saucepan.
Remove from heat.
Add lemon juice, zest, and butter. Stir until butter is melted.
You may add yellow food coloring to the dessert sauce to make it more yellow if you'd like. Start with just a drop or two then stir. Keep adding food coloring to get the desired color. This sauce is best served warm. Store leftover sauce in an airtight container in the refrigerator. I like to use a glass jar. The sauce will thicken as it cools. It will also get thinner when reheated. Warm lemon sauce in the microwave before serving.If you'd like a thinner sauce just add a few Tablespoons of water until you get the desired consitency you'd like.