CARAMELIZE THE ONIONS: Position a rack in the center of the oven and preheat the oven to 400ºF. In a large cast-iron skillet over medium heat, melt the butter with a small drizzle of oil (any kind.) Add the onions and sauté them for 5 minutes or until they start to sweat and shrink a little. Lower the heat to medium-low, season with sugar and Italian seasoning and continue to cook for 25 minutes or until the onions start to turn golden and caramelize. You want to just stir the mixture every 5 minutes or so. If the onions are caramelizing too fast, you can turn the heat down a little bit. Prepare and bake your meatballs while the onions are caramelizing to save time. 

MEATBALLS:  In a medium bowl, using a fork, mix together all the ingredients except the chicken. When the ingredients are combined, add the ground chicken and mix until *just* combined. Shape the mixture into 1 tablespoon mixture (roughly 30 meatballs?) Place the meatballs on a baking sheet lined with parchment paper, about 1 inch apart and bake for 18–22 minutes or until the meatballs are moist but a bit firm to the touch (or they reach an internal temperature of 165ºF.)

FRENCH ONION SAUCE: If your meatballs aren’t done, you can turn the stove off until they’re finished then pick the recipe up. Deglaze the pan with the Worcestershire sauce, season with salt, and add the minced garlic. Kick the heat up to medium and continue to stir and cook. Sprinkle the flour and cook for 30 seconds, slowly drizzle with the beef stock with one hand while you continue to stir the sauce with the other hand. Allow the sauce to gain a simmer and cook for 1-2 minutes or until the sauce thickens. Add the meatballs into the sauce and then sprinkle the cheese over the top and turn the stove off. Cover with a tight-fitting lid and allow the cheese to melt. Alternately, you can place the skillet in the oven under the broiler for 1-2 minutes for the cheese melt (be sure to only use the broiler if your skillet is oven safe!)