Let the butter and oil melt in a tall pot.
Peel the onions, cut them in half and slice them thinly, add them to the pot along with the bay leaves and thyme.
Let it cook for about 10 minutes or longer until the onions start to color nicely.
Add the broth, bring to a boil, taste, season with pepper, salt, and balsamic vinegar.
Let it simmer for another 5 minutes.
Slice the baguette, place them on a baking sheet, and generously cover them with the grated cheese.
Set your oven to grill mode and grill for 5 to 8 minutes until the cheese is nicely melted and colored.
Scoop a bowl of onion soup and place 1 or 2 toasts on top and finish with finely chopped parsley.
Nestle into the couch and enjoy!
Tips
No extra tips needed, Just Enjoy!