Created by KittenCal on January 28, 2012
Step 1: Add the lemon rind to boiling water, reduce heat and simmer for 5 minutes.
Step 2: In a small bowl combine the cornstarch with sugar and salt; add the boiling water/lemon zest mixture slowly and whisking constantly. Return to saucepan; cook whisking over medium heat for 10 minutes or until thickened. Lower heat and simmer for 3-5 minutes longer.
Step 3: Remove from heat. Stir in lemon juice and butter until thoroughly combined