Preheat oven to 375°F and line a small baking dish with parchment paper.
In a small skillet, sauté the finely diced yellow onion and minced garlic until translucent and fragrant.
In a large mixing bowl, combine the ground beef, ground turkey, whisked egg, almond flour, sautéed vegetables, sea salt, black pepper, and dried oregano.
Gently mix 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 half of the glaze over the top of the loaf.
Bake for 35-40 minutes, then apply the remaining glaze and bake for another 10 minutes until the internal temperature reaches 165°F.
Let the meatloaf rest for 5-10 minutes before slicing to ensure it stays juicy.