Christina's Lime Curd

from Mother Earth News

• 1-1/2 cups granulated sugar
• Zest of 4 limes (avoid the white, pithy parts)
• 2 large eggs, plus 2 large egg yolks
• 1/2 cup freshly squeezed lime juice
• 1 stick (8 T or 1/2 cup) salted butter, cut into 16 pieces
• 1 tsp vanilla extract

1. Process the lime zest with the sugar in the food processor for about 3 minutes or until very thoroughly mixed.

2. In a medium-sized saucepan, thoroughly whisk together the sugar, eggs, and yolks. Whisk in the lime juice and salt and place over med-low heat. Add the butter 1 piece at a time, slowly whisking as each one completely melts into the mixture before adding the next. Switch out the whisk for a rubber spatula, and continue to cook over med-low heat, stirring gently but consistently until the mixture has thickened enough to leave a momentary trail in the bottom of the pan when you run your spatula through the center—the mixture should part just long enough for you to see the metal of the pan as the spatula scrapes the bottom, but it will run back together fairly quickly. This will take about 15 minutes.

3. Remove the pan from the heat, stir in the rum or vanilla, and allow to cool completely, stirring occasionally, before transferring to an airtight container. Store in the fridge until ready to use, up to three days.