First, wash the zucchini and slice it into rounds. Place the zucchini slices in a 9 1/2-inch skillet (24 cm) with a drizzle of oil and cook for 7-8 minutes, just until slightly tender.

In a bowl, beat the eggs with an electric mixer and add a pinch of salt. Add the milk (or water, if you prefer) and chives, and continue beating until the mixture is light and frothy. By now, the zucchini should be cooked just right—be careful not to break them. Pour the egg mixture over the zucchini and cook over medium-low heat.

Cover the frittata with a lid and cook until the surface is set and no liquid remains. Then, using a plate or a lightly greased lid to help, flip the frittata and cook on low heat for a few more minutes. And there you have it—your frittata is ready!