Wash potatoes if necessary and cook covered in water for about 20 minutes. In the meantime dice the ham. Cut the cucumbers lengthwise like a fan, but don't cut through at the end.
Drain the potatoes and rinse with cold water. Peel immediately, preferably using a potato fork in the skin. Leave to cool a little. Peel and finely chop the onion. Cut the potatoes into slices.
Heat 1 tbsp. lard in a frying pan. Fry half the potatoes for about 10 minutes until golden brown, turning from time to time. Season with salt and pepper. If you have two pans, fry both portions in parallel.
Fry half onion cubes for 5 minutes. Whisk the eggs and season with salt and pepper. Pour half over the fried potatoes. Turn the potato slices quickly in the eggs.
Slide the edges of one side of the pan together and allow to set for 5-6 minutes over medium heat. If necessary, preheat the oven to the lowest setting to keep the first farmer's breakfast warm.
Place a large plate on the pan. Press against each other and turn it over with swing. Keep the farmer's breakfast warm if necessary. Fry the second one in the same way. Serve with ham, cucumber, tomato wedges and parsley.