Wash the potatoes and cook in plenty of boiling water for 25-30 minutes. Wash, clean and quarter the tomatoes. Cut tomato quarters into cubes. Peel and finely dice onion. Wash marjoram, dab dry and chop, except for something to garnish. Mix minced pork, tomatoes, onions and marjoram and season with a little salt and pepper.
Drain the potatoes, rinse with cold water and remove the skin. Halve potatoes lengthwise and put them into 4 greased ovenproof dishes. Put the minced meat mixture on the potato halves and press them down a little. Sprinkle with cheese and spread fat in flakes on top. Bake in a preheated oven (electric: 200 °C/ gas: level 3) for about 15 minutes. Serve garnished with marjoram