- 2 T olive oil
- 4 onions, sliced
- 2 cloves crushed garlic
- 2 T brown sugar
- 3 cups beef stock
- 1-2 T balsamic vinegar
- Fresh ciabatta
To a large saucepan over a medium to low heat, add olive oil, sliced onions and cloves crushed garlic. Gently fry to soften.
Add brown sugar and beef stock. Simmer for 10 minutes, then stir in balsamic vinegar and season to taste.
Cut fresh ciabatta into thick slices and toast under a hot grill. Top with slices of Gruyère and slide under the grill again until melted and bubbling.
Ladle the soup into deep bowls and top with Gruyère-ciabatta croutons.