Heat a large, heavy-bottomed pot to medium heat and melt the butter. Add in the sliced onions and cook, stirring every now and then until softened, about 15 minutes or so. Add the salt and pepper and continue cooking, stirring occasionally until caramelized, 45 - an hour. https://thefoodieandthefix.com/wp-content/uploads/2018/01/DSC_6151-2.jpg Raise the heat to high on your burner and add in the sherry, deglazing the pan and getting up all of the browned bits on the bottom. Cook on high for about 10 minutes or so, or until most of the liquid has evaporated. Keep an eye on this to make sure it doesn't burn towards the end when there is little liquid left. Add in the broth and the herbs (tying them together with some cooking twine so you can remove them easily). Continue cooking on high until it comes to a bubble, then turn down the heat a bit until it's at a good simmer (this was about medium-high on my stove, but it's electric, so it would probably be lower on a gas stove), then simmer uncovered for another half an hour or so until the broth has thickened and it tastes so freaking good you want to drink it. Croutons: Preheat oven to 375 degrees. Lay out the bread cubes on a baking sheet, lightly spray them with cooking spray and sprinkle lightly with a bit of thyme and garlic powder, toss. Bake for about 8-10 minutes, flipping them over halfway through or until they're dried out and toasted. (Once these are completely cool, you can put them in a baggie and they'll keep for several days!) To Serve: Put 1 1/3 cup of hot soup in each soup crock, top each with 6 croutons, then cover each with a slice of cheese. Pop them under the broiler on low until cheese melts. (I usually don't bother preheating the broiler, but feel free!) Be sure to watch it carefully so the cheese doesn't burn. This took about 2 minutes under my broiler, but each is different. You could also use a kitchen torch to melt the cheese if you've got one (I'm always looking for an excuse to use my kitchen torch!). Enjoy!