Cut pumpkin into 1x1 inch diamonds. Wash and clean the zucchini squash and cut it into 1/2 inch slices. Peel the onions and cut each of them into eight wedges. Cut each of the lamb fillets into quarters. Arrange the ingredients on skewers.
Wash and peel the potatoes and cut them into wedges. Remove fresh thyme leaves from the stems, chop them up and combine half of them with salt, pepper and 50 ml oil. Coat the potatoes in the oil and bake them in the preheated oven at 400 degrees F for approximately 20-25 minutes.
Peel and finely mince the garlic and combine it with the remaining oil, thyme, salt and pepper. Coat the pumpkin lamb skewers with the oil mixture, briefly brown the skewers in a sauté pan, then place them in the preheated oven at 350 degrees F for about 15 minutes.
For the dip combine yogurt, mayonnaise, chili powder, cayenne pepper, salt and chives. Arrange the skewers with the potato wedges and cubes of pickled pumpkin and serve with the yogurt dip.