Make candied nuts: Melt butter in skillet, add sugar and let mostly melt until bubbling. Add nuts, stir 2 minutes, then spread on parchment to cool. Chop half, leave some whole.
Plump cranberries by soaking in freshly boiled water for 10 minutes, then drain.
Toss apple slices with lemon juice to prevent browning.
Combine all dressing ingredients in a jar, shake well until blended.
Assemble: Place salad leaves in bowl with half the apple slices and all onion. Add half the dressing, toss gently.
Top with cranberries, candied nuts, remaining apple, and cheese. Drizzle with remaining dressing just before serving.