In a small bowl whisk together the mayonnaise, yogurt, mustard, honey, 2 tbsp lemon juice and apple cider vinegar. Whisk till smooth. If you would like it thinner, just add more lemon juice, 1 tsp at a time. Season well with salt and pepper. This can be made in advance and stored in the fridge till needed.
Serve
Wash, spin and dry the lettuce leaves. Spread them on a platter. Place the chopped dressed salad evenly over the lettuce leaves. If you didn't add the chicken to the bowl with the salad, arrange decoratively on top of the salad now.
Scatter the remaining walnuts and chestnuts all over the salad. Drizzle more of the dressing over the salad. Finish with the pumpkin and sunflower seeds, and fresh herbs if using. Serve.
As with any salad, feel free to play with the amount of ingredients. If you really like grapes add more, want to use less walnuts, go for it! You get it!
For poaching method for chicken, see my Chicken Taquitos for the complete method.