Casa Dani

A market-stall counter inside Mercado de la Paz frequently named the best tortilla de patatas in Madrid — thick, molten in the centre, and served in wedges at bar height to a queue that starts before the market fully opens.

It's counter and bar-table service only, inside the Mercado de la Paz market hall, and gets a genuine queue by mid-morning — go right at opening for the shortest wait. The tortilla is sold by the wedge and portions run generously; one slice with bread is a substantial snack, not just a taste. It's cash-friendly and unpretentious despite the reputation.