Sweat the onions when they are nice and translucent, add the tomato paste and stir quickly until the tomato paste turns brown. Be careful that it doesn`t burn!
Always add a little vegetable stock and deglaze the tomato paste. Repeat the process over and over to get a sauce. Then add the rest of the broth.
Peel the potatoes, cut into long, narrow slices and add to the broth. After 15 minutes add the beans, carrots and leek and let cook.
After another 20 minutes, season to taste with the spices and, if necessary, thicken with a little sauce powder. The whole thing should have the consistency of a thin sauce.