Cook the potatoes in boiling water for 20-30 minutes. Drain and rinse in cold water. In the meantime, clean, wash and slice the onions finely. Take about 4 tablespoons aside for garnishing.
Cut the ham into small pieces (tear). Melt 1/2 tablespoon of clarified butter in a frying pan and fry the ham pieces crisply for about 4 minutes. Take something aside for garnishing. Peel and slice the potatoes.
Heat 1 tablespoon of lard in 2 pans. Fry 1/4 of each potato slice for about 7 minutes while turning. After 5 minutes add 1/4 each of ham and onions. Season with salt and pepper. Whisk two times 3 eggs and season with salt and pepper.
Pour eggs over the potatoes and bring to a halt. Shortly before, push the potato and egg mixture together into the edge of the pan, let it falter to the end and turn out of the pan onto a plate. Keep the finished omelettes warm and repeat the process.
Spread the remaining ham cubes and onion slices on the omelettes.