That egg whites can be frozen for at least a year but to freeze egg yolks you need to add sugar to keep them from getting too sticky and unusable.
For 1 egg yolk/about 1 tablespoon/0.6 ounce/18 grams stir in ½ teaspoon/2 grams sugar. Don’t forget to remove the sugar from the recipe after defrosting the yolks.
My favorite healthful lunch is 0 fat Greek yogurt with 1 heaping teaspoon of lemon curd swirled in and a handful of blueberries.
Classic Lemon Curd
Makes: 1-1/4 cups /330 grams
Have ready near the range a strainer, suspended over a medium bowl containing the lemon zest. In a heavy saucepan, whisk the yolks, sugar, and butter until well blended. Whisk in the lemon juice and salt. Cook over medium-low heat, stirring constantly with a silicone spatula (be sure to scrape the sides of the pan), until thickened and resembling hollandaise sauce, which thickly coats the spatula but is still liquid enough to pour. The mixture will change from translucent to opaque and begin to take on a yellow color on the spatula. It must not be allowed to come to the boil or it will curdle. Whenever steam appears, remove the pan briefly from the heat, stirring constantly, to keep the mixture from boiling.
When the curd has thickened, pour it at once into the strainer and press it through with the spatula. Stir gently to mix in the zest sitting in the bowl (there will be about 1/3 cup/90 grams leftover after filling a cake). Allow the curd to cool for 30 minutes. Cover tightly and refrigerate until no longer warm--about 3 hours. Store refrigerated in airtight jar or container, 3 weeks. (Longer storage dulls the fresh citrus flavor.)