Marcella Hazen's Zucchini, Onion, and Basil Frittata
New: December 2019

oil
1 large onion, thinly sliced
3 (or 2.5) medium zucchini (used 3 the first time, over flowed)
5 eggs (used 6 the first time, over flowed)
butter

Salt, pepper

Use 8 inch cast iron