Makes a generous 2 cups
While I use this curd for the cranberry version of my Eton Mess, I like having a jar in the fridge to serve with other fruit desserts and ice cream. Curd is most traditionally made with lemon juice, but you can make it with lime, grapefruit and/or orange juice — a mixed-citrus curd is nice. If you use orange, include some lemon juice too — it will give the sweet orange juice some needed edge.
Working Ahead
You can refrigerate the curd in an airtight container for at least 3 weeks.
Whisk the sugar, eggs, corn syrup and lemon juice together in a medium heavy-bottomed saucepan. Drop in the pieces of butter.
Put the saucepan over medium heat and start whisking. You want to get into the corners of the pan, so if your whisk is too big for the job, switch to a wooden or silicone spatula. Cook, continuing to whisk — don’t stop — for 6 to 8 minutes, until the curd starts to thicken. When it is noticeably thickened and, most important, you see a bubble or two come to the surface, then stop; the curd is ready.
Immediately scrape the curd into a heatproof bowl or a canning jar or two. Press a piece of plastic wrap against the surface to create an airtight seal and let the curd cool to room temperature, then refrigerate.