Boil the potatoes for 20–25 minutes in salted water until they are soft. Heat the milk and butter in a small pan until the butter melts. Heat the olive oil, garlic and sage in a saucepan over medium heat until you can smell the garlic. Add the chickpeas and sauté for a few minutes so that the flavours of the garlic and sage mingle with the chickpeas. Remove the garlic and sage. Purée the chickpeas with a hand-held blender until they are completely smooth and silky, adding
Mash the potatoes or pass through a potato mill into a wide bowl which you can eventually use for serving. Add the remaining milk and butter mixture and mix it in well. Fold in the chickpea purée and taste for salt. Serve warm or at room temperature, drizzled with extra virgin olive oil if you like.