Heat up a large pot and add the bacon lardons and cook until crispy. When done remove and set a side, leave the rendered bacon fat in the pan
reduce heat to low and add the onions and a bit of unsalted butter. Keep your eye on the onions. stir and cook until they are golden brown, the darker the better but do not burn them. Add a bay leaf
Remove the pan from the heat and add in the madeira wine and stir.return the pan back to the heat, reduce so all the wine is absorbed into the onions. Add the dried thyme here and heat up I actually use less dried than I do fresh. (If you are using fresh wait until the stock is added)
Add the stock and other bay leaf the rind from the cheese (sounds weird but it adds so much flavor to the soup that makes you go yum) return the crispy bacon to the pot (and fresh thyme if you are using it do not use both fresh and dried thyme) simmer. taste for seasonings and adjust.
Turn on the broiler. In an oven safe bowl place some cheese and add the onions and broth. Place the toasted cheese topped baguette slice onto the soup add some shredded grated gruyere cheese on top and place under the broiler until golden brown and melty deliciousness.