You can easily triple this recipe and serve it to company. Use a cast-iron pan and instead of flipping the frittata stovetop, finish it in a hot oven and then invert onto a plate to serve.
In a small nonstick skillet, sauté the shallot in 1 tablespoon of olive oil over medium-low heat. When they begin to become tender, add the zucchini. Sauté the vegetables until they are cooked through and beginning to brown, about 4 minutes. With your spatula, spread the zucchini and shallots evenly across the base of the pan. Season the egg with salt and pepper and pour it over the vegetables.
Cook until the bottom of the frittata has set and the top is nearly cooked through, about 3-5 minutes. Using a spatula, loosen the bottom of the pancake. Peel back one side, and tilt the pan so that the remaining uncooked egg slides to the open surface area. Using a second spatula, gently flip the frittata. Sprinkle the cheese over the top, and cover the pan with a plate to lock in the heat. Cook for another minute or so until the cheese is melted and the underside of the frittata has set. Slide the frittata onto a round plate and serve immediately.