Sear the sausages in sunflower oil, then add the leek and fry briefly. Now distribute the pasta on top. Dissolve the stock cubes in 1 liter of warm water and pour the stock over the pasta until it is covered. Bring to the boil and cook covered, until the noodles are cooked (according to the instructions on the packet).
Remove the saucepan from the hob and stir in the tomato paste.
The sauce shouldn`t be too runny, but wonderfully creamy and tomato-like.