Lime Curd

Directions

1. 1
   Bring sugar, zest, and juice to a boil in a heavy nonaluminum 3 1/2-qt. saucepan over medium-high heat. Remove from heat, and gradually whisk about one-fourth hot juice mixture into egg yolks; add egg yolk mixture to remaining hot juice mixture, whisking constantly until well blended.
2. 2
   Place saucepan over medium heat, and cook, whisking constantly, at least 10 or up to 12 minutes. (Mixture will be a pudding-like thickness.)
3. 3
   Add butter, in 6 batches, whisking constantly until butter melts and mixture is well blended after each addition. Remove from heat, and pour mixture through a wire-mesh strainer into a bowl. Place plastic wrap directly on warm curd (to prevent a film from forming); chill 3 hours.