Alioli (literally “garlic and oil”) originated in Catalonia, but is now eaten everywhere. It is basically an emulsion of olive oil with garlic and a little salt, but eggs are often added to thicken it and make garlic mayonnaise. It is not too difficult to make from scratch, but there are some very good ready-made versions around. An acceptable cheat is to use shop-bought mayonnaise with garlic purée to taste.