Seasonal product cooking built on the market around it: they buy fish and vegetables from the neighbouring stalls first, and supply other restaurants in turn. Fermentation is a cooking technique for them, not a lab exercise, used to keep produce at its peak and to build flavour. Dishes that have appeared include devilled eggs filled with prawns and a mayonnaise made from a stock of their heads, a tomato slow-baked for 12 hours with pistachio, parmesan and mint, hake with cuttlefish consommé and shiso, a pumpkin tocino de cielo with sheep's milk, tigres of mussel with béchamel and kimchi, a yuca waffle with oyster and clam chowder sauce, and an oyster po'boy in brioche.

The shop side sells what the kitchen uses: kimchi, which is always on and the best seller, sauerkraut, fermented red cabbage, house mustards, artisan pickles, habanero sauces and kombuchas, plus a salmon they marinate themselves, cheese from Cameros in La Rioja and cecina. Almost everything is made in house; the oysters, cheese and cecina are the exceptions. You can take any of it home, and eat in at the few tables by the bar.

They prefer to call them live wines rather than natural wines, and there are about 60 references from small producers in Spain, France, Italy, Georgia and the Czech Republic, organic and biodynamic, in white, red, rosé and sparkling, aged in bottle, wood, clay or steel. They started pouring them before natural wine became a trend in Madrid, because they like wines that show the grape, the place and the person who made them, and the pitch at the bar is to come without prejudice and try.