Pour water and lentils into a large pot and boil on medium heat for 20-30min or until the lentil gets soft and the first layer of skin separates.
Meanwhile, slice tomatoes in half and grind the flesh on large hols of a vegetable grater, leaving the skins behind. Set aside.
Chop carrot, potato, and celery into bite-size pieces. Next chop onion in a fine cube.
Add oil, grated tomato, all of the chopped vegetables, and spices (cumin, paprika, ginger) into a pot. Follow with chopped garlic cloves and tomato puree. Stir all the ingredients well together and simmer on medium heat for 30-40min until the potato is cooked and the soup gets thick.
Season with salt to taste and serve with freshly chopped coriander sprinkled on top. Great with a side of crunchy bread for dipping.