First make the dressing. Put all ingredients except the mayonnaise & yoghurt into a small food processor. Blend until you get a coarse paste. Transfer to a large serving bowl and add the mayonnaise & yoghurt. Season to taste and combine well.
Slice the fennel and cabbage very thinly - keep the fronds of the fennel.
Peel then quarter the apples, remove the core and thinly slice. Place these in a small bowl and squeeze over some lemon juice to prevent the apple discolouring.
Add the sliced vegetables and apple to the large bowl with the dressing and toss well. Garnish with the fennel fronds before serving.