Preheat your oven to 375°F and line a small baking sheet or loaf pan with parchment paper.
In a medium mixing bowl, combine the lean ground beef, egg, almond flour, finely diced yellow onion, minced garlic, sea salt, black pepper, and dried oregano.
Mix the ingredients by hand until just combined, being careful not to overwork the meat which can make it tough.
Form the mixture into a compact loaf shape and place it on the prepared baking sheet.
In a small ramekin, whisk together the tomato paste, apple cider vinegar, and maple syrup to create the glaze.
Brush the glaze evenly over the top and sides of the meatloaf.
Bake for 35 to 40 minutes, or until the internal temperature reaches 160°F.
While the meatloaf bakes, steam the green beans until they are tender-crisp and bright green.
Allow the meatloaf to rest for 5 minutes before slicing to ensure it stays moist, then serve alongside the steamed green beans.