Peel the courgettes and cut them into thick slices, peel and dice the potatoes.
Heat a few tablespoons of olive oil in the bottom of a pot and add the courgettes together with the potatoes, lemon zest, turmeric, black pepper and chilli pepper. Stir thoroughly and sauté over low heat for 10 minutes. At the very end, fish out a few slices of courgette and set aside to serve.
After that, pour the broth into the pot and cook for another 5 - 8 minutes. When the vegetables are very soft, blend everything into a smooth cream, season to taste with lemon juice, salt and black pepper. Serve with slices of fried courgette, sprinkled with black sesame seeds and coriander or parsley leaves.