The Easiest Lemon Curd 

Using a microwave to cook lemon curd streamlines the entire process, and eliminates the need to stand over the stove whisking constantly. The result is silky-smooth and as tart as you like. Use the smaller amount of sugar for a puckery curd, and more for something with greater balance. Once you get the technique down (and it may take some finessing since everyone’s microwave is a bit different), you can vary the citrus, substituting lime or grapefruit for lemon, and seasoning it with makrut lime leaves or Campari (see Tips). Curd will keep in the fridge for at least five days; serve it with cookies or fruit, fold it into whipped cream to make lemon mousse or spoon it into a tart shell for a glossy lemon tart.

Ingredients

• ½

  cup/113 grams unsalted butter (1 stick)

• 2

  teaspoons finely grated lemon zest

• 1

  cup freshly squeezed lemon juice (4 to 6 lemons)

• ¾

  cup to 1 cup granulated sugar

• 3

  large eggs

• 1

  egg yolk

• Pinch of salt

Preparation

1. Put the butter in a large (at least 6 cup) microwave-safe glass bowl or measuring cup. Set your microwave on 50 percent power and melt the butter, about 1 to 1 1/2 minutes.
2. Pour butter into a blender and add lemon zest, juice, sugar, eggs, egg yolk and salt. Blend until smooth. Pour mixture into the same glass bowl you melted the butter in. (You don’t need to wash it.)
3. Microwave the curd mixture, on full power, in 1-minute intervals for 5 minutes. Whisk furiously between intervals, especially around the edges of the bowl. It should start to thicken. (If it looks like it’s starting to thicken before 5 minutes, stop and continue to the next step; microwaves can vary.)
4. Reduce power to 70 percent and continue to microwave for another 1 to 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.
5. Whisk well and inspect the curd. If you think there are any coagulated bits of egg, strain curd through a fine-mesh sieve into a clean bowl. Or if it looks smooth, you can leave it in its current bowl. Press a piece of plastic wrap against the surface to create an airtight seal and let the curd cool to room temperature. Refrigerate until cold, at least 3 hours.