Peel and wash the potatoes and cut into large cubes. Clean, wash and cut the leek into rings. Slice the sausages. Heat oil in a roasting pan. Fry the sausage slices in it while turning them, take them out. Sauté potatoes and leek in frying fat. Season with salt, pepper, 1 pinch of sugar and paprika.
Add tomato paste and sauté briefly. Fold in slices of sausage. Deglaze everything with approx. 400 ml water. Bring to the boil, cover and stew for about 15 minutes. Add tomatoes, bring to the boil and continue to braise for about 5 minutes.
In the meantime wash the chives and cut them into fine rolls. Season goulash with salt and pepper and fold in chives.