Rhubarb Curd

Place chopped rhubarb in a medium-sized saucepan. Add sugar, water, lemon juice, and salt. Bring to a boil over medium heat, reduce heat to medium-low and cook, stirring occasionally, until rhubarb is soft, about 10 minutes.

Pour rhubarb mixture into a mini food processor or blender; blend until smooth, 10 to 20 seconds. Reserve 1/3 cup and return remaining rhubarb mixture to saucepan over low heat.

Whisk egg yolks together in a small bowl. Slowly add reserved rhubarb mixture, whisking constantly. Slowly whisk egg-rhubarb mixture back into the saucepan and continue whisking for 5 minutes, or until mixture is thickened and the curd coats the back of a metal spoon. Whisk in butter until melted and fully incorporated.

Pour into a sterile jar and cool. Curd keeps in the refrigerator for up to 1 week.