Trim the ends off each onion then halve lengthwise. Remove Peel and finely slice into half moon shapes. Add butter to deep pot. Once butter has melted add a layer of onions and sprinkle with a little salt. Repeat layering onions and salt until all onions are in pan. do not try stirring until onions have sweated down for 15 to 20 minutes. After that, stir occasionally until onions are dark mahogany and reduced to approximately 2 cups. This should take 45 min. to 1 hour. Don't worry about burning.
Add enough wine to cover the onions and turn heat to high, Reducing the wine to a syrup consistency. Add Consume, chicken broth, apple cider. Reduce heat an simmer 15 to 20 min.
Place oven rack top 1/3 of oven and heat the broiler.
Cut bread in rounds large enough to fit the mouth of oven safe soup crocks. Place the sliced on a baking sheet and place under broiler for 1 min.
Season soup mixture with salt, pepper an cognac. Ladle soup into crocks leaving 1 inch to the lip. Place bread round, toasted side down, on top of soup and trop with grated cheese. Broil until cheese is bubbly and golden, 1 to 2 minutes.