Lemon curd is so versatile: You can use it to fill tart shells, top ice cream, or coat cookies. Watch Everyday Food editor Sarah Carey make one of her favorite homemade treats.
In a medium saucepan, off heat, whisk together sugar, zest, and egg yolks; whisk in lemon juice and salt.
Add butter and place pan over medium-high. Cook, whisking constantly, until butter has melted, mixture is thick enough to coat the back of a spoon, and small bubbles form around the edge of pan, about 5 minutes (do not boil).
Remove pan from heat while continuing to whisk. Pour curd through a fine-mesh sieve into a glass bowl. Press plastic wrap against the surface of curd and refrigerate until cool.
To store, refrigerate in an airtight container, up to 2 weeks.