Set the Oven to 150 degrees.
Make a bouquet garni and tie a string around the herbs (do not need this but will make it easier to remove it from the soup).
Cut the onion into thin slices.
melt butter in a saucepan and brown the onion lightly.
Add the stock and bouquet garni, bring to the boil.
Turn down the heat when it boils and let the soup simmer under the lid for 30 min.
Remove the bouquet garni and season with salt and pepper.
Roast slices of the baguette
Pour the soup into refractory soup bowls and cover the soup with toast.
Sprinkle grated cheese over.
Put the soup bowls in the oven at 150 degrees and leave them until the cheese is golden brown.
