Mix the flour, 3 eggs, 2 tbsp. oil, 2 tbsp. lukewarm water and 1 tsp. salt first with the dough hooks of the hand mixer, then with your hands to a smooth, supple dough (at least 10 minutes kneading time!)
Form the dough into a smooth ball, wrap in foil and let it rest for about 30 minutes.
Put the spinach in a pot with a little water. Cover and cook over low heat for about 15 minutes, stirring several times. Drain and let cool down. Soak the rolls in cold water. Peel and chop 1 onion.
Wash the parsley, shake dry. Pluck off leaves and chop finely. Press the sausage meat out of the skin. Squeeze the spinach well, chop a little if necessary. Squeeze the bread roll.
Knead minced meat, bread roll, sausage, parsley, spinach and 2 eggs. Season with pepper and 1 1/2-2 teaspoons salt. If necessary, cut a small dumpling from the meat mixture with teaspoons and cook in boiling salted water.
If the mixture is too unseasoned, it can still be seasoned.
Cut the dough in half. Press half of the dough flat on a floured work surface. Roll out the dough thinly (approx. 15 cm wide, approx. 80 cm long) with the pasta machine (not wafer-thin!). Spread half of the dough on a well floured work surface, leaving about 1 cm free at the long upper edge and about 4 cm free at the long lower edge.
Brush the 1 cm wide edge with some water. Fold the lower edge over the filling, then fold the filling up to the upper edge and press the edges firmly. Use a wooden spoon handle to divide the roll of dough into 8 Maultaschen, pressing the dough very firmly together.
Cut the Maultaschen apart and press the sides firmly together again. Place Maultaschen on a floured baking tray or tray. Process the remaining dough and mince in the same way.
Peel 2 onions and cut or slice into thin rings. Wash the chives, shake dry and cut into fine rolls. Heat 3 tablespoons of oil in a frying pan and fry the onion rings until golden brown.
Bring the meat stock to the boil and let the Maultaschen simmer for 6-8 minutes. Arrange the Maultaschen with the stock in portions on plates. Add onions and sprinkle with chives.