The primary ingredient in a quiche is eggs. Quiche is a savory dish that consists of a pastry crust filled with a mixture of beaten eggs, cream, and various other ingredients like cheese, vegetables, and meats. The versatility of quiche allows for unlimited variations, making it a popular choice for brunch or light meals. The eggs provide the necessary structure and richness to the filling, while the addition of cream creates a smooth, custard-like texture. Quiche can be served hot or cold and is often accompanied by salads for a complete meal.