Onions peel and chop finely. Potatoes peel, wash and roughly dice. Pumpkin clean, peel, wash and also roughly dice. Wash, peel and quarter apples and cut out the cores.
Dice apple quarters. Heat oil in a pan and sauté onions. Add pumpkin, potatoes and apples, fry briefly and deglaze with broth and apple juice. Bring to the boil, cover and simmer over medium heat for 20-25 minutes.
Meanwhile, wash the thyme, dab dry and pluck the leaves from the stalks. Add half of the leaves to the soup about 10 minutes before the end of the cooking time. Remove the soup from the heat and puree.
Season to taste with salt and pepper. Sprinkle soup with remaining thyme and serve sprinkled with pumpkin seeds as desired. Pluck lilac berries from the umbels, wash thoroughly and drain well on a sieve.
Add lilac berries to the soup and bring to the boil briefly.