Shred or dice the leftover turkey into even pieces.
In a medium sized mixing bowl whisk together the yoghurt, mayonnaise, mustard, salt and lemon juice until smooth. Follow with the dill and chives until evenly mixed in.
Add in the turkey, diced gherkins and diced celery and mix well. Set aside whilst you prepare your salad vegetables.
Shred the lettuce, dice the beetroot, avocado, olives, red pepper and cucumber and slice the radishes.
Arrange the vegetables and salad ingredients around the edges of a bowl. Either in individual bowls or a large serving bowl. Mound the dressed turkey in the centre of the bowl.
In a small mixing bowl whisk together the olive oil and the juice of half the lemon with the salt and pepper. Drizzle the dressing over the top of the salad vegetables.
Finish the bowl with a scattering of the parsley leaves.