Wash the potatoes thoroughly and cook in salted water for about 20 minutes. Put eggs in boiling water and boil them hard for about 10 minutes
For the vinaigrette, peel and finely dice the shallots. Heat oil in a pot and sauté shallots for about 2 minutes. Deglaze with vinegar and stock and simmer for about 3 minutes. Stir in mustard, season to taste with salt, sugar and pepper, cool down. Wash parsley, shake dry. Pluck off leaves and chop finely. Mix into the vinaigrette
Clean and wash the radishes and cut them into fine slices. Clean and wash the watercress and remove the leaves. Drain the potatoes, let them cool down a bit and cut them in half. Mix the radishes, watercress, potatoes and vinaigrette. Peel and quarter the eggs. Fill salad into bowls. Place 2 egg slices and 3 slices of ham on each salad and serve immediately