Maultaschen - also known as German Stuffed Pasta - are definitely worth the effort. These mouthwatering "mouth bags" filled with ground meat, spinach, and onion are served in a hot broth or fried in butter and served with fried onions!
First, make the pasta dough (alternatively you can buy pre-made pasta dough). For that, mix the flour, eggs, salt, oil, and water first using the spiral dough hooks of your electric mixer. Then - towards the end when the dough is better mixed - use your hands. Keep kneading with your hands until the dough has an elastic consistency. Then form it into a ball and set it back into the bowl. Cover the bowl with a dishtowel and set it aside.
Now, it's time for the filling. If you're using a stale bun for the bread component, soak it in water for a few minutes until soft. You might have to place something onto the bun so it stays underwater. Squeeze out the excess water and set it aside.
Finely chop the onion and sauté it in a frying pan in one teaspoon of oil until translucent. Remove the pan from the heat and let the onions cool slightly.
Wash the spinach, then boil it for 2-3 minutes in a pot of water. Remove it from the pot and run the spinach under cold water. Squeeze out the water, then chop the spinach into small pieces.
In a large mixing bowl, combine the ground pork, ground beef, chopped spinach, eggs, chopped parsley, and sautéd onion. Also, rip the soaked bun into small pieces and add it - or add the breadcrumbs. Finally, add salt, pepper, and nutmeg and mix everything together using your clean hands. If the mixture is overly wet, add a few more breadcrumbs. When you're happy with the consistency, place the bowl with the meat mixture in the fridge.
Now it's time to roll out the pasta dough. You can either do that by using a pasta maker or rolling it out by hand using a rolling pin and lots of flour. To make it easier, separate the dough into two parts of equal size. Use one half and briefly knead it with your hands. Then add flour to your countertop and roll it out until it is approximately 30 inches by 9 inches in size and quite thin. This might take a while - add more flour as needed.
Thinly spread half of the meat mixture onto the rolled out pasta dough, leaving at least 1 inch of space at the top, bottom and sides. Now fold the long bottom part over, just under halfway, and press down. Now tuck in the left and right edges. Fold the long bottom part over again and press down again. Brush some water onto the top edge without meat and flip it over to "seal the dough".
Now use the handle of a wooden spoon and firmly press down approximately every 2.5 inches. Then cut the dough along these pressed lines using a pizza cutter or sharp knife. Press down along the edges of the small Maultaschen again, if necessary. However, you don't need to worry if some of them don't close - the filling shouldn't spill out during boiling if you are gentle. Repeat the same steps with the second half of the pasta dough and the meat mixture.
Bring a large pot with salted water to a boil and reduce the heat to medium-low once boiling so that the water is just simmering. Add the first batch of Maultaschen to the pot (don't add too many, they need enough space to float to the top) and let them sit in the hot water for approximately 15-20 minutes until done. Gently run a wooden spoon along the bottom of the pot every once in a while to make sure no Maultaschen are sticking to the bottom. When they rise to the top, you know they are (almost) done. Let them sit in the hot water for a couple more minutes, then remove the Maultaschen with a straining spoon.
Serve the Maultaschen in hot vegetable or beef broth (just place the Maultaschen on a deep plate, pour a little hot broth over them) or fry them in some butter and serve with "melted" onions (onions that are gently fried in butter with some water added every once in a while until the onions are nicely golden brown).
Don't put too much filling on the dough or else it will be very hard to fold and close properly.
Be gentle when you are boiling the Maultaschen - place them in gently and remove them gently, too.