Blanch the peas in little boiling salted water for about 2 minutes. Drain, rinse and drain well. In the meantime cut ham into strips. Peel and finely chop the onion.
Whisk eggs and milk. Season with salt and pepper. Heat 2 tablespoons of oil in a large coated pan (28 cm Ø). Fry ham and spaetzle in it while turning. Add peas and pour the egg milk over them.
Cover and allow to set at low heat for about 15 minutes.
In the meantime, clean, wash and drain the salads and pluck them into pieces. Mix vinegar with salt, pepper and 1 pinch of sugar. Fold in 4 tablespoons of oil. Mix vinaigrette with salad and onion. Cut omelette into pieces, sprinkle with fried onions and serve.