In a medium bowl, combine the ground beef, egg, almond flour, garlic powder, onion powder, sea salt, and black pepper until just incorporated.
Form the beef mixture into two oval-shaped patties, approximately 3/4-inch thick.
Heat the olive oil in a large skillet over medium-high heat and sear the patties for 4 minutes per side until a golden crust forms, then transfer them to a plate.
In the same skillet, add the thinly sliced yellow onion and cook for 5 minutes until softened and lightly caramelized.
In a small jar or bowl, whisk together the beef broth, coconut aminos, and arrowroot powder until no lumps remain.
Pour the broth mixture into the skillet with the onions, stirring constantly as it simmers and thickens into a velvety gravy.
Return the patties to the skillet, spooning the hot gravy over them to coat, and serve immediately alongside fresh steamed green beans.