Remove the skin from the meat sausage and cut into slices (or pieces). Peel and halve the cucumbers and remove the seeds with a teaspoon. Scald the beefsteak tomatoes with boiling water, rinse with cold water and peel them immediately. Cut into large pieces. Peel and finely dice the onion.
Fry the sausage in hot fat. Add the cucumber and onion and sauté briefly. Season to taste with salt, pepper and sugar. Deglaze with approx. 100ml water, then stir in the cream and mustard and let simmer for approx. 10 minutes. Just before the end of the cooking time, fold in the tomato pieces. Sprinkle with chopped parsley.