8-10 finely chopped onions,
2 spoons olive oil,
1 pinch of sugar
3 spoons flour,
Salt and pepper
100 gr grated parmesan
Gruyere cheese finely chopped
In a casserole dish, melt the butter on a moderate heat. Add the olive oil and the very finely chopped onions. Cook on a low heat for about 10 minutes stirring continuously until the onions take on a golden color.
Add the sugar, the flour, a pinch of salt and pepper, some white wine and mix all the ingredients together. At this point pour in the vegetable broth which has been previously prepared and brought to the boil.
Cook for a further 30 to 40 minutes.
In the meantime, toast the slices of bread in the oven.
When the soup is ready, pour it in earthenware containers and put the finely chopped gruyere cheese and the toasted bread on top. For an extra touch of flavour, also add some grated cheese.
If you want to see the video with the procedure just click here