Wash the potatoes and cook in salted boiling water for 20 minutes.
Meanwhile, clean the cauliflower, cut into small florets, wash well and drain in a colander. Cook the cauliflower florets in plenty of boiling salted water for about 5 minutes until al dente. Immediately lift from the boiling water with a slotted spoon and allow to drain.
For the dip, stir the 200 g sour cream with 2 tablespoons of grainy mustard until smooth and season with salt and pepper. Halve each of the 4 cherry tomatoes and quarter them if necessary.
Drain the potatoes, collect them in the colander and rinse briefly with cold water. Peel off the peel with a knife and cut in half.
Heat 2 tablespoons of oil in a pan and fry the potatoes all around until golden brown. Cut the Leberkäse into bite-sized cubes. Add cauliflower florets and meat loaf cubes to the fried potatoes and sauté briefly. Season savory with salt and pepper.
Divide between 2 plates and put a good dollop of sour cream and mustard dip on each before serving.
Arrange the tomato pieces decoratively on the two plates and sprinkle everything with a little fresh, chopped parsley.