In a Dutch oven or cast iron pot, heat the olive oil on medium heat and brown the meat on all sides. Remove with a slotted spoon.
Add the onion, garlic, and celery to the pot, stir, and sauté until the vegetables are soft.
Return the meat and any juices to the sautéed vegetables and then add the cilantro, parsley, tomatoes, cumin, turmeric, paprika, lentils, salt, and pepper. Mix well and add the water and tomato paste.
Bring to a boil, reduce the heat, and simmer for 1 1/4 hours.
Dissolve the flour in the tablespoon of cold water and stir into the soup. Add the chickpeas and cook for another 15 minutes.
To serve, squeeze one lemon quarter onto each bowl of soup.