Over medium heat, heat the olive oil in large heavy-bottomed saucepan.
Peel, halve and thinly slice the onions. Then add them to the pot with a stir.
Continue to stir the brown sugar and Worcestershire Sauce until the onions turn a deep golden color.
Mix in the garlic and cook until fragrant.
Mix the butter and flour in a saucepan. Stir everything together.
Stir in the wine.
Add the stock to the soup, then add the herbs. Let the soup simmer for a while.
Season with salt & pepper
Take out the bay leaf and thyme stems. Ladle the soup in heat-safe bowls or slow cookers. Top with cheese and toasted bread.
Place the cheese under the broiler until it is browned and bubbly.