ZUCCHINI POTATO FRITTATA 1 medium zucchini or yellow summer squash, sliced Salt 4-5 T extra-virgin olive oil, or more as needed 1 1/2 lbs waxy potatoes, thinly sliced 1 large onion, halved and thinly sliced 6 eggs Freshly ground black pepper 1 cup grated Cheddar (from Andrea Chesman's 'Serving Up the Harvest')