How to Make It
Preheat the oven to 250°. On a work surface, toss the zucchini with the salt. Divide the zucchini between 2 large colanders set in the sink. Set plates directly on the zucchini and weight them down with canned goods. Let the zucchini drain for 15 minutes. Squeeze out the excess water, then spread the zucchini on a triple layer of paper towels and blot the zucchini as dry as possible.
Lightly oil 2 large rimmed baking sheets. Spread the zucchini evenly in the pans and bake for 2 hours, stirring the zucchini a few times, or until it reduces in volume by two-thirds but is still moist. Let cool completely. Transfer 1- or 2-cup portions to sturdy plastic bags or airtight containers and freeze for up to 6 months; defrost before using.