Prep - Line a rimmed baking sheet with parchment paper or foil for easier cleanup, and preheat oven to 350°F. Sautee Onions - Set a medium skillet over medium heat. Add 1 tsp oil and chopped onion and saute, stirring occasionally, until softened and golden, about 5-7 minutes. Transfer to a plate to cool. Make the Meatloaf Mixture - In a large bowl, add all of the meatloaf ingredients and mix just until well combined (your hands are your best tool for mixing - put on disposable gloves if you want to). Shape Meatloaf and Bake - Add meat to the pan and shape it into a meatloaf about 8 inches long, 4 inches wide, and 3 inches tall. Bake uncovered at 350˚F for 40 minutes. Make the Sauce - In a small bowl, add the sauce ingredients and stir to combine. Add the Glaze - Spread the sauce over the Meatloaf, then return to the oven and bake an additional 20 minutes or until the internal temperature is 160˚F on an instant-read thermometer. Rest the meatloaf for 10-15 minutes before serving and it will be much easier to slice.