Classic onion soup

Method

1. In a large pot saute the onion slowly with the oil until very soft and mushy but not very brown.  This could take over an hour so please be patient. 
2. When the onion is thoroughly cooked add the chicken stock and vinegar and bring to the boil, continue to cook slowly for 15 minutes
3. Serve with some fresh herbs if available and wholegrain bread

For a vegetarian option just replace the chicken stock with vegetable stock.