Meanwhile, set a sauté pan to medium heat, add the oil and onion, carrot, celery and garlic and sauté until the onions are translucent, 2-3 minutes. Turn off the heat and allow to cool while you prepare the rest of the ingredients
In a large mixing bowl, scramble the egg, then add the beef, turkey, milk, bread crumbs, parsley, thyme, Italian seasoning, salt and pepper
Add the sautéed vegetables and gently mix with your hands until all the ingredients are well incorporated
Place the meatloaf on a parchment lined baking sheet and spread out into a 2-inch thick oval
Bake for 20 minutes
Meanwhile, whisk the ketchup, brown sugar and apple cider vinegar and brush half of the mixture on the meatloaf
Bake for another 5 minutes, brush the remaining ketchup and bake for 5 more minutes before serving