(by Lisa S. Greene)
(adapted from Melissa Clark of The New York Times)
1 stick unsalted butter
2 t. finely grated lemon zest
1 c. freshly squeezed lemon juice (from 4 - 6 lemons)
3/4 - 1 c. granulated sugar, to taste
3 large eggs
1 egg yolk
pinch of salt
Put butter in a large (at least 6 c.) microwave-safe glass bowl or measuring cup.
Set microwave on 50 percent power, and melt butter, about 1 - 1 1/2 minutes.
Pour butter in a blender and add lemon zest, juice, sugar, eggs, egg yolk, and salt.
Blend until smooth.
Pour mixture into the same glass bowl used for melting the butter.
Microwave the mixture on full power, in 1-minute intervals for 5 minutes.
Whisk furiously between intervals, especially around edges of the bowl. It should start to thicken.
(If it looks like it’s thickening before 5 minutes, stop and continue to the next step.)
Reduce power to 70 percent and continue to microwave for another 1 - 2 minutes, whisking every 30 seconds, until the curd thickens enough to coat a spoon, and looks slightly puffed and spongy. (It will continue to thicken as it chills.) An instant-read thermometer should register 180 degrees.
Whisk well and strain the curd through a fine-mesh sieve into a clean bowl.
Press a piece of plastic wrap against the surface and cool to room temperature.
Refrigerate until cold, at least 3 hours.
Makes 2 cups.
(Read Where's My Knife?, the story that accompanies this recipe.)