Sweet potato crumble

According to John Gerard’s Herball (1597), this fluorescently orange tuber ‘used to be eaten rosted in the ashes’ then dressed with oil, vinegar and salt. ‘Notwithstanding how they be dressed, they comfort, nourish and strengthen the body.’ If you tire of roasting them in the ashes, try this humble crumble with a crisp and buttery breadcrumb topping. Make your own soft breadcrumbs by whizzing some good stale bread in the food processor.