1. Cut all the onions into half rings and mince the garlic

2. Heat the butter in a big pot and add the onions and garlic. Let it all caramelize until golden brown
3. Deglaze with a splash of cognac

4. Add stock, salt, pepper and thyme, bay leave. Let simmer

5. Make slices from the baguette and drizzle with olive oil, toast lightly in the oven.

6. Assemble by filling a cup with the soup followed by a bed of cheese, some slices of baguette and some more cheese. In the oven under the boiler until the cheese is melted.

7. Serve with some parsley and enjoy!

Stock

1. Give the bone marrow some color in the oven

2. Roughly chop the onion, garlic, celery and carrot

3. Add oil to a pan and fry down the veggies. Go in with the bone marrow (with bones), water, parsley, bay leaves and peppercorns. Add salt to taste

4. Let simmer for as long as possible

5. Strain the stock through a fine sieve.