Wash and clean the peppers and aubergines and cut them into medium-sized pieces. Peel, wash and quarter the potatoes. Peel and finely chop the onion. Peel garlic and chop finely.
Heat the oil in a pot and fry the onion in it until golden brown. Add prepared vegetables, except for 1 small potato to bind, and fry briefly. Add garlic and paprika powder, stir-fry and add the stock.
Wash the rosemary and thyme and dab dry. Add bay leaf, rosemary and thyme, except for 1 stalk for garnishing, and simmer for 15-20 minutes. Grate the rest of the potatoes finely and stir into the goulash about 10 minutes before the end of the cooking time.
Season with salt, lemon peel, caraway and pepper. Arrange aubergine goulash in a bowl and serve with a dollop of sour cream. Pluck off the remaining thyme and sprinkle the goulash with it.