Preheat oven to 375°F and line a small loaf pan or baking sheet with parchment paper.
Heat olive oil in a small skillet over medium heat and sauté the onion and garlic until soft and fragrant.
In a large mixing bowl, combine the ground beef, egg, almond flour, sea salt, black pepper, dried thyme, and the sautéed onion mixture.
Mix gently with your hands until just combined, being careful not to overwork the meat.
Shape the mixture into a loaf and place it in the prepared pan.
In a small bowl, whisk together the tomato paste, apple cider vinegar, and maple syrup to create the glaze.
Bake the meatloaf for 20 minutes, then brush the savory glaze evenly over the top.
Return to the oven and bake for another 15-20 minutes until the internal temperature reaches 160°F and the glaze is tacky.
Let the meatloaf rest for 5 minutes before slicing to ensure it stays juicy.