That extends to dishes like escabeche de níscalos, saffron milk cap mushrooms in a vinegar marinade, and a black truffle ice cream for dessert, exactly the kind of course that backs up the idea that mushrooms show up everywhere on the menu, not just the savory half.

El Brote began as a bar specialising in mushrooms on Calle Chile, and in 2014 moved to a larger space on Calle Javier Ferrero, where Roncal's cooking reached haute-cuisine level. The pace there was relentless, and in 2016, with the restaurant full every day, the three decided it was no way to live and closed. About a year later they came back, this time in a small, cosy room with exposed brick on Calle de la Ruda, a few steps from the Mercado de la Cebada and Plaza de Cascorro, seating around 20 to 30. Every table and chair is different, part of the charm.

The menu is five courses plus dessert, €57 at the latest listed price, which the restaurant notes changes with the market, and there's a vegan and vegetarian option if you say so when booking. The mushrooms are gathered or bought by the team, and the current run moves from pickled shiitake with tomato and figs to wood ear mushroom with green beans, plums, watercress, mint, peanut and sweet potato purée, morels with beetroot, cheese and baby spinach, black trumpets with roasted squash, mole, fried rice and pomegranate, and chanterelles with baby squid, small potatoes and a herb picada, finishing with a house bay-leaf ice cream.

Past menus have included angula de monte, a wild mushroom that looks like baby eels, with egg yolk, black truffle over whiting with Jerusalem artichoke, and a black truffle ice cream. In autumn and winter Roncal leans towards wild fruits, chestnuts and a little game; in spring and summer, towards lighter, fresher plates. The restaurant has said the menu changes most in spring and autumn, when mushrooms are at their peak, and it closes in summer.

The wine list is short and personal, with notes on every bottle. The house white and red are Torrederos, from €2.95 a glass, and the list runs through Madrid wines like Bernabeleva's Navaherreros, Txakoli from Gorrondona, Albariño, Alsatian Riesling and a handful of natural wines, to reds such as Envínate's Albahra, César Márquez's Parajes from Bierzo, 4 Monos' Cien Lanzas from the Sierra de Gredos, made in clay tinajas, and Artuke's Finca Los Locos from Rioja Alavesa.

El Brote is at Calle de la Ruda 14 and opens Tuesday to Saturday for lunch and dinner. Book through its site or by phone or WhatsApp on +34 652 17 33 19; it's a small room and tables go quickly.