This is a quick and easy variation on the flat Spanish-style tortilla or Italian frittata. Instead of making one quite thick omelet, you make seven thin one --one plain and six with different flavorings--that cook in no time. You then stack them up and cut through them all so each layer tastes different. It is a great dish to serve with drinks at a party or as a snack.
Organization is the key here, so get your own little production line going. Have seven little bowls or glasses ready in front of you, each containing 2 eggs, 1 teaspoon milk, and a few twists of salt and pepper. Behind all but the first (which is going to be plain) have a bowl or glass with each of the flavorings: finely diced mushrooms; finely diced zucchini; skinned, deseeded, and finely diced tomato; finely diced or grated Gruyère; finely grated Parmesan; and finely chopped herbs.
Line a flat baking sheet with parchment paper, ready to stack the omelets on as you cook them.
For 6 as an appetizer or 24 party portions
For each of the 7 omelets
2 large eggs (preferably free-range)
1 teaspoon milk
sea salt and freshly ground black pepper
1 teaspoon vegetable oil
For the flavorings
2 button mushrooms
1/4 cup grated Gruyère
4 tablespoons Parmesan
small handful of mixed herbs, e.g., a few leaves of fresh sage, rosemary, thyme, and oregano
1. Heat 1 teaspoon of vegetable oil in a frying pan (about 8 inches in diameter) over medium heat. Ideally, use a nonstick omelet pan or a frying pan that you use regularly and know won't stick.
2. Quickly whisk your first set of eggs and milk with a fork and pour into the pan, lifting and tilting it so that the egg covers the whole of the base. Cook for about 11/2 minutes until the egg looks just cooked on top, and then slide it gently out of the pan onto your parchment paper. Don't overcook it; you will be putting another omelet on top of it in a minute or so, and as you keep on adding layers the heat of each omelet will continue to cook the one beneath.
3. Put another teaspoon of oil into your pan. Whisk your second set of eggs and milk, and repeat, but this time as soon as you spread the eggs over the pan, scatter over your first filling--in this case, the mushrooms. Cook for 1 1/2 minutes, as before, and then slide on top of the plain omelet.
4. Continue in this way until you have one plain and six different-flavored omelets sitting one on top of the other. Then put another sheet of parchment paper on top of the stack and press down gently. The oil in each omelet will help them all to stick together as one.
5. You can serve the layered omelet warm or cold. Either way, cut into big wedges, or smaller bite-sized squares. If you want to serve small squares at a party, skewer them with toothpicks so that people can pick them up easily.