Beat the butter and sugar, then add the egg, salt, and lime zest.
Gradually add the flour, kneading as little as possible to prevent gluten development.
Let it rest in the refrigerator for half an hour.
Oven bake at 160 degrees for 12 minutes.
Enjoy!
Notes
Before put in the oven, prick the bottom of the pie pan with a fork to prevent it from puffing up during baking, as this allows steam to escape and the base to remain flat and even..