Ajillo oil is a delicate and delicious chilli condiment. It is made with garlic and guajillo, a mild dried chilli known for its fruity flavour and for staining food with its deep, brick-red colour. In Mexico, the oil is used to season seafood dishes, but I find many uses for it in my kitchen when I’ve made a batch. Here, I toss chestnuts in it and use it to drizzle over an autumnal risotto; the roundness of the chilli and garlic make a bewitching contrast to the sweetness of the squash.
