|butter — and olive oil, for frying|
|wine — or water|
Slice onions thinly, season with a pinch of salt and sauté slowly in a mixture of butter and olive oil until the onions are caramelised. Add a little white wine or water, and reduce until the mixture is fragrant and syrupy. Serve as a filling for baked potatoes, on pizzas, in stews or kneaded into bread dough.