Quarter and roughly dice the white cabbage. Also quarter the onions, separate them in layers, and put them in a large saucepan with the cabbage, salt, pepper and a pinch of sugar and fry for about 10 minutes.
In the meantime, halve the zucchini lengthways, cut into slices and add and fry briefly.
Then deglaze with a cup of broth and let simmer for about 30-45 minutes (depending on the desired firmness).
Season with Tabasco and, if you like, stir in a tablespoon of sour cream.