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 and bouquet garni. Reduce heat and simmer 15 to 20 minutes.
Place oven rack in top 1/3 of oven and heat broiler.
Cut country bread in rounds large enough to fit mouth of oven safe soup crocks. Place the slices on a baking sheet and place under broiler for 1 minute.
Season soup mixture with salt, pepper and cognac. Remove bouquet garni and ladle soup into crocks leaving one inch to the lip. Place bread round, toasted side down, on top of soup and top with grated cheese. Broil until cheese is bubbly and golden, 1 to 2 minutes.