In a bowl, combine flour, salt, baking soda, cornstarch, and salt.
In a separate bowl mix melted butter and sugars.
Add eggs, vanilla, and sourdough discard and combine.
Add half of the flour mixture to the wet mixture. Stir until mostly combined. Add remainder of the flour mixture. Stir until combined and thick.
Fold in chocolate chips.
Refrigerate cookie for at least 30 minutes,
Preheat oven to 350 °F
Scoop cookie dough onto cookie sheet using a large cookie scoop ( I use an ice cream scoop).
Bake for 12 minutes,
Allow cookies to cool on the cookie sheet for 5 minutes before moving to a cooling rack.