Beyond the carrillera and the pepitoria quail, the menu runs to parrocha, Huelva red prawns with reduced poultry stock and a crispy chip, a lobster-roll-style fried squid sandwich with citrus aioli, and smoked trout with roe, fino wine sauce and crispy pork powder. Bread comes from Madreamiga and olive oil from Bernabeleva, and the cocktails go by the name 'aguaduchos.'

Alex de la Fuente began at the Escuela Superior de Hostelería in 2004 and trained under Santi Santamaría, Fernando P. Arellano and Ricardo Sanz. At Punto MX he learned the origins and secrets of Mexican cooking from Roberto Ruiz, and he then spent five years as head chef alongside Ramón Freixa at his two-Michelin-star Madrid restaurant, where he learned to care for every detail. In-Pulso, in his words, was born from the persistence to realise a dream and to cook always from the heart. It holds a Michelin Bib Gourmand.

The carta feeds on Madrid's traditional castizo recipe book and customs, with updated technique and a personal eye, recovering forgotten recipes, from a dish said to be Felipe III's favourite to a Golden Age breakfast, with a Mexican thread woven through. Snacks start at €5, such as a free-range-egg tortilla pintxo and house-pickled Ibérico shad. Mains include a squid sandwich with citrus aioli, melting beef tongue with Nordic crab, Huelva red prawns al ajillo, house-smoked trout with its roe and fino sauce, shredded beef cheek and 'enriched' quail pepitoria (€25), and cod pil-pil. Bread comes from Madreamiga and olive oil from Madrid.

The six-course Menú Castizo, served to the whole table and pitched as a sensory journey through the city's history, is listed at €60 on the carta; the gift version with wine pairing costs €85. Once a month, on a Wednesday night, In-Pulso runs 'Un paseo por las calles de Madrid', a seven-course menu with each dish inspired by a street, corner or legend of the city.

The cellar leans on Spanish small producers, from Corpinnat sparkling wines by Gramona and Recaredo to Envínate and Algueira, with a couple of Champagnes. The house cocktails are called aguaduchos, a tribute to the street kiosks that once sold homemade refreshments such as barley water and horchata around Madrid: the Pichi, the Chotis, El Chulapo and La Violetera, each €10.

Once a month, on a Wednesday evening, In-Pulso turns dinner into a history lesson: 'Un paseo por las calles de Madrid', seven courses, each inspired by a street, a corner or a legend of the city, with the stories told alongside. It's where de la Fuente brings out the recipes he digs up from Golden Age novels and old palace cookbooks, from the dish said to have been Felipe III's favourite to a Golden Age breakfast. It costs €65, or €85 with wine pairing.

The regular carta keeps a castizo backbone. It opens with €5 bites, a pincho of tortilla made with free-range eggs, grilled beef picada on puff pastry, and parrocha in house escabeche with Kalamata mayonnaise; moves on to a squid sandwich with citrus aioli, melting veal tongue with Nordic crab and paprika hummus, and Huelva red prawns al ajillo; and runs to mains of 'Cibeles' trout smoked in-house with its roe and fino sauce, shredded veal cheek, quail in pepitoria with a pâté of its innards, and salt cod pil pil with asparagus, at €24 to €26. The six-course Menú Castizo costs €60 for the whole table, and the desserts include letuario, the old Madrid orange preserve, here as a cream and sorbet with candied peel in honey.

In-Pulso serves lunch Tuesday to Saturday from 13:30 to 15:15 and dinner Wednesday to Saturday from 20:30 to 22:15, and is closed on Sunday and Monday. Book through the reservations link on its site, call 91 162 03 20, or email hola@inpulsorestaurante.com. The room, near the Planetarium in Legazpi, is decorated with vintage cookbooks, with chotis and zarzuela playing.