Sweet Potato Stackers and other Christmas nibbles. Cut sweet potatoes into 1cm discs,  toss with oil and some seasoning on a baking sheet. Roast 20-30 mins at gas 6 until golden and crisp on the outside, then leave to cool. To serve, mix mayonnaise with lemon juice. Pile a scrunched up piece of prosciutto on each star, top with a blob of mayo. | Butcher, Baker
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