5 egg yolks
1 cup sugar
4 limes, zested and juiced
1 stick butter (4 oz.), cut into pats and chilled
- Add enough water to a medium saucepan to come about 1-inch up the side. Bring to a simmer over medium-high heat.
- Combine egg yolks and sugar in a medium size metal bowl and whisk until smooth, about 1 minute.
- Add juice and zest to egg mixture and whisk smooth. Once water reaches a simmer, reduce heat to low and place bowl on top of saucepan. (Bowl should be large enough to fit on top of saucepan without touching the water.)
- Whisk until thickened, approximately 8 minutes, or until mixture is light yellow and coats the back of a spoon.
- Remove promptly from heat and stir in butter a piece at a time, allowing each addition to melt before adding the next.
- Remove to a clean container and cover by laying a layer of plastic wrap directly on the surface of the curd. Refrigerate for up to 2 weeks.