Cut the spring onions lengthways into very thin strips then slice the turkey into long pieces. Keep at room temperature.
Whisk together the cider vinegar, sugar and mustard in a large bowl. Season, then slowly trickle in the oil in a thin stream, whisking all the time, to give an emulsified dressing. Add the mange tout, cherry tomatoes and mint and stir well to coat.
Arrange the turkey around the serving plates and sprinkle the spring onions over the top. Add the lettuces to the mange tout mixture then toss gently to coat. Pile mange tout salad on top of the turkey and spring onions and serve straight away.
© Phil Vickery