If using fresh spinach, blanch in boiling water for 1-2 minutes until wilted. If using frozen spinach, thaw completely. Squeeze out as much liquid as possible through a colander, then chop finely and set aside.

Heat butter or oil in a pan and sauté the minced onion until translucent and fragrant.

Add ground beef to the pan, breaking it up with a wooden spoon as it cooks until just browned through. Set aside to cool slightly.

Soak bread slices in milk or water until soft, then squeeze out excess moisture.

In a large bowl, combine spinach, beef mixture, and crumbled bread. Season with nutmeg, salt, and pepper.

Add beaten eggs and mix thoroughly until it forms a cohesive paste that holds together when pressed but remains somewhat soft.

Lay out wonton wrappers and place about 1-2 teaspoons of filling in the center of each.

Brush the edges with the egg-water mixture, then fold in half to create half-moon shapes. Press edges firmly to seal.

Bring a large pot of salted water to a rapid boil and gently drop in the Maultaschen.

Cook for 8-10 minutes until they float to the surface and look slightly puffed.

Serve traditionally in clear beef broth, pan-fried with eggs, or topped with browned butter and toasted breadcrumbs.