Wash the potatoes and cook in boiling water for about 20 minutes. Meanwhile clean the cauliflower, divide into small florets, wash and drain. Cook the cauliflower in boiling salted water for about 5 minutes.
Remove and put aside. Stir sour cream and mustard until smooth and season with salt and pepper. Drain the potatoes, rinse and peel. Halve the potatoes. Heat the oil in a pan and fry the potatoes in it until golden all around.
Cut Leberkäse into medium sized pieces. Add the cauliflower and Leberkäse to the potatoes and fry. Season with salt and pepper. Garnish with parsley and a dash of mustard and sour cream dip and serve.