Soak the chickpeas in plenty of water for about 12 hours.
Then pour into a sieve and drain. Sort and wash the lentils. Wash and peel the potatoes and carrots. Wash and clean the celery. Cut the potatoes into small cubes, the carrot into slices and the celery into thin strips. Peel the onion and chop finely. Peel the garlic.
Rinse the meat with cold water, pat dry and cut into small cubes. Heat the olive oil in a large saucepan and then fry the meat with the onions for about 3 minutes. Put the garlic through the press. Add the potatoes, carrots and celery, fry briefly and deglaze with the meat stock. Add the chickpeas and lentils and simmer covered for about 1 hour over low heat. Skim off the resulting foam in between.
In the meantime, scald the tomatoes with boiling water, peel them, remove the stalks and puree with a hand blender or blender. Wash the parsley, shake dry and finely chop without the coarse stems. After 1 hour of cooking, add the tomato puree, parsley, rice, lemon juice, harissa and spices to the soup, stir well and cover and cook for about 20 minutes.
Mix the cornstarch with a little cold water and add to the soup while stirring. Season the dish with salt and pepper and serve with flatbread or baguette.
In the fasting month of Ramadan, nothing is to be eaten between sunrise and sunset. This soup opens the menu in the evening.