The first time I tried romesco I was spending an afternoon in La Barceloneta, Barcelona’s beach neighbourhood. It came as a dip with patatas bravas (a roasted potato tapas dish that’s usually served with a lightly spicy tomato aïoli) and it was absolutely glorious. This delicious red pepper and almond sauce is originally from Tarragona, in Catalonia, and the fishermen in the area made it to be eaten with fish. Romesco can be found on menus across Spain and for all the right reasons. It adds a layer of flavour to any dish, such as these cauliflower tostadas, a hearty and nutritious vegetarian dish that will also be a hit with meat eaters.