Wash the potatoes and cook in boiling water for about 20 minutes, drain, quench, peel and slice. Peel and chop onion
Heat 1 tablespoon of lard in 2 coated pans. Add 1/4 of each potato slices and fry for approx. 7 minutes, turning until brown. Season with salt and pepper. After about 4 minutes add 1/4 of each onion. Remove half of each potato from the pan and keep warm
Whisk 2 eggs twice and season with salt and pepper. Pour the eggs over the potatoes in the pan. Shortly before the mixture sticks, carefully push them together with a spatula. Let it falter to the end and turn out of the pan onto a plate, cover with warm potatoes, fold up and keep warm. Prepare 2 more omelettes from the remaining ingredients as described
Cut the cucumbers fan-like. Wash parsley, shake dry. Peel and chop the leaves. Arrange cucumber and ham on the omelette plates, sprinkle with parsley