Make a pasta dough from the flour, salt, eggs, and water, mixing until combined and smooth.
Finely chop the onion and ham. Drain the thawed spinach thoroughly. In a bowl, combine the drained spinach, minced meat, sausage meat, 2 eggs, breadcrumbs, chopped onion, and chopped ham. Season with salt, pepper, nutmeg, marjoram, and parsley to taste. Refrigerate the filling if not using immediately.
Divide the pasta dough into 3-4 portions. Roll each portion thinly into a rectangular shape. Place small mounds (about 2 teaspoons each) of filling at regular intervals along one half of each dough rectangle. Fold the other half over the filling and press firmly around each mound to seal. Using a pastry wheel, cut the maultaschen apart between the sealed mounds. Press the edges firmly to seal well.
Bring a large pot of salted water to a boil over high heat. Carefully add the maultaschen and cook for about 10 minutes until they float and are cooked through. Remove with a slotted spoon and rinse immediately under cold water to prevent sticking.
Serve the maultaschen in warm clear broth garnished with chives, or pan-fry them in a skillet over medium heat with sliced onions until golden, stirring in beaten eggs until cooked.