Peel and finely dice the onion and the garlic. Peel and slice the carrots. Peel and cut the potato into small chunks. Wash and drain the lentil. Cut the lemon into 6 wedges. Pick the mint leaves, discard the stalks.
Preheat some oil in a pan and add the onion and carrot at the same time. Saute about 3-4 minutes then add the potato chunks with a good pinch of chilli flakes and mix in the tomato paste as well. Cook more 2 minutes, stirring continuously. Finally add the lentil and pour 900 ml stock in the pan. Season with salt and ground black pepper.Bring to the boil, then reduce the heat and simmer for 20 minutes, or until the lentils are tender. With a blender mix the soup thoroughly, if it is too thick, you can add some more stock and adjust according to your sense of taste.
Serve it with chopped fresh mint, a dollop yoghurt and on the top and sprinkle with some sumac and chilli flakes. Add couple drops of lemon as well.
«If you want to make it more rich instead of stock sometimes Turkish people add just milk as a liquid. »