Preheat the oven to 450° F. Grease a 9×13 inch baking dish with olive oil.Take the bread and run it under water until dampened but not soaked. Gently squeeze the excess water out of the bread and then crumble the dampened bread into pieces.In a bowl, combine the chicken, bread crumbles, egg, and a pinch each of salt and pepper. Coat your hands with olive oil, then roll the meat into balls about the size of 2 tablespoons, and place them into the prepared baking dish. Bake for 15 minutes or until the meatballs are crisp on the outside, but not yet cooked through on the inside.Meanwhile, melt together the butter and onions in a large oven safe skillet over medium-high heat. Cook, stirring occasionally until softened, about 10 minutes. At this point, you'll want to slowly add 3/4 cup of the wine, 1/4 cup at a time, until the wine cooks into the onions. Continue to cook another 10-15 minutes until you've used all of the 3/4 cup of wine and the onions are deeply caramelized. Add the garlic, mushrooms, thyme, and sage. Season with salt and pepper, cook another 3-4 minutes. Add the the broth and a pinch each of salt and pepper. Increase the heat to high and bring to a low boil. Add the meatballs and simmer 10 minutes, until cooked through. Stir in the cream.Arrange the bread on a baking sheet and toast for 10 minutes, until very dry. Switch the oven to broil. Place the bread on/around the meatballs. Top evenly with cheese. Broil until bubbly and golden brown, 3 to 5 minutes. Top with fresh thyme. Eat!