Ingredients
6 large onions
100 g sugar
4 tbsp balsamic vinegar
1 tbsp olive oil

Finely slice the onions and sauté them in the olive oil until translucent. Add the sugar and vinegar, cook on high heat for 10 minutes to allow the vinegar to evaporate, then cover and cook on very low heat, stirring occasionally, for 1 hour...

Serve as an accompaniment to foie gras, duck...