Preheat your oven to 375°F (190°C) and line a small loaf pan or baking sheet with parchment paper.
Finely dice the yellow onion and carrot, and mince the garlic clove.
Heat the avocado oil in a small skillet over medium heat and sauté the onion, carrot, and garlic until softened and fragrant, about 5 minutes.
In a large mixing bowl, combine the ground beef, egg, almond flour, sautéed vegetables, sea salt, and black pepper.
Gently mix the ingredients by hand until just combined, being careful not to overwork the meat to ensure a tender texture.
Shape the mixture into a loaf on the prepared baking sheet or press it firmly into a loaf pan.
In a small bowl, whisk together the tomato paste, balsamic vinegar, and maple syrup to create the savory glaze.
Spread half of the glaze evenly over the top of the meatloaf.
Bake for 35-40 minutes, or until the internal temperature reaches 160°F (71°C), brushing with the remaining glaze halfway through the cooking time.
Remove from the oven and let the meatloaf rest for 5-10 minutes before slicing to allow the juices to redistribute.