With only a handful of ingredients this zucchini gratin is incredibly easy to make, and yet what comes out of the oven is a rich creamy gratin with a blanket of crisp, flavorful cheese on top.
Put the zucchini in a colander and sprinkle with the salt. Toss to coat evenly with salt and leave the zucchini in the colander set over a bowl for one hour. The salt not only seasons the zucchini it draws out extra water, preventing your gratin from getting soggy.
Add the Gruyère, potato starch and ground nutmeg to a bowl and toss to combine evenly.