This curd goes with our Passion-Fruit Icebox Cake.
Combine sugar, puree, and yolks in a large mixing bowl, and whisk together.
Set bowl over pan of simmering water; whisk until thick enough to coat back of spoon, 15 minutes. Cook about 5 minutes.
Remove bowl from heat; stir in butter, piece by piece, until melted. Cool, cover with plastic, and refrigerate until needed.
