Mix sugar, corn starch, salt, and water and put in microwave on high until thick (3 min. or more)
Combine Egg Yolks and Butter, and mix a little of the hot mix into the eggs, to keep yolks from curdling. Return to microwave for 1 more minute.
Stir in Lemon Juice and Zest and place in baked pie shell
(For lime pie, reduce corn starch to 1/3 c.)