In a bowl, combine all the ingredients; ground meat, eggs, breadcrumbs, Worcestershire sauce, black pepper, ground nutmeg, sea salt, garlic, onion powder, and ground coriander.
Mix the ingredients with your hands. Try to form an even, fine texture without big lumps.
Let the ingredients sit in the fridge for an hour. This lets the flavors mix well, and the meat becomes sturdier. The resting time helps the meat not fall apart when seared.
Separate the mix into 4 equal parts. Form thick and firm patties with your hands.
Preheat a cast-iron skillet with the butter on high heat, and transfer the patties into the searing hot butter.
Turn down the heat to medium, and sear the hamburger steaks in the preheated butter for approximately 4-5 minutes per side until they are brown.
Plate the hamburger steaks and pour some spoonfuls of gravy over them. Serve them with mashed potatoes, oven-baked sweet potatoes, glazed carrots, or green beans.