Preheat your oven to 375°F (190°C) and line a 9x5-inch loaf pan with parchment paper for easy removal.
Finely dice the yellow onion and mince the garlic cloves until they are very fine to ensure they blend seamlessly into the meat.
In a large mixing bowl, combine the lean ground beef, ground chicken, eggs, all-purpose flour, onion, garlic, parsley, thyme, rosemary, sea salt, and black pepper.
Gently mix the ingredients by hand until just combined, ensuring the herbs and aromatics are evenly distributed without overworking the meat to maintain a tender texture.
Press the mixture into the prepared loaf pan, smoothing the top with a spatula to create an even surface.
In a small bowl, whisk together the tomato paste, Dijon mustard, and coconut aminos to create a clean, savory glaze.
Spread the glaze evenly over the top of the meatloaf using the back of a spoon or a pastry brush.
Bake for 50 to 55 minutes, or until the internal temperature reaches 160°F (71°C) when measured with a meat thermometer.
Remove from the oven and let the meatloaf rest in the pan for 10 minutes before slicing to allow the juices to redistribute for a moist result.