Tortilla Española, also known as Spanish omelette, is a classic dish in Madrid. It is made with eggs, potatoes, and onions, cooked together to form a thick and hearty omelette. The tortilla is typically served in slices and can be enjoyed as a tapa, a light meal, or even as a sandwich filling. Tortilla Española is a versatile and delicious dish that is loved by locals and visitors alike.