Preheat oven to 375°F and line a small baking dish with parchment paper.
In a large mixing bowl, combine the ground beef, egg, almond flour, diced onion, minced garlic, sea salt, black pepper, and dried thyme.
Mix gently by hand until just combined, being careful not to overwork the meat.
Shape the mixture into a uniform loaf and place it in the prepared baking dish.
In a small bowl, whisk together the tomato paste and balsamic vinegar to create the glaze.
Spread the glaze evenly over the top of the meatloaf.
Bake for 35-40 minutes or until the internal temperature reaches 160°F.
Let the meatloaf rest for 5 minutes before slicing to ensure it stays juicy.