Chop the onion, cut the carrots and potatoes into pieces, chop the savoy cabbage, chop the parsley, cut the leek into rings, cut the sausages into small pieces.
Fry the onion, leek, carrots, parsley and the celery slice in the margarine, then deglaze with the stock. Add the potatoes and cabbage, season with gyros and let simmer gently for 30 - 35 minutes, with the lid half-open, stir carefully from time to time. Finally, take out the celery slice! (If you like, you can of course cut the celery into small pieces and eat it too.)
Then add the chopped sausages. Season with salt and pepper if necessary.