30g or 1oz of butter
2 tablespoons of sunflower oil
675g or 1½ lbs of onions, halved, and thinly sliced
2 cloves of garlic crushed
½ teaspoon of caster sugar
1 litre or 1¾ pints of vegetable stock (I always use marigold stock powder)
2 teaspoons of yeast extract or marmite
290ml or ½ pint of dry white wine
Heat the butter and oil in a large heavy saucepan. Add the onions, garlic and sugar and cook over a medium heat for 30 minutes, or even longer, stirring from time to time until the onions are soft and richly caramelized.
Add the stock, yeast extract and wine and bring to the boil. Lower the heat, cover and leave to simmer for a further 30 minutes.
The onions never go totally brown, but you want them really really soft and gooey and sticky. The tiny amount of sugar helps them go a bit darker.
The yeast extract makes the soup go much more brown, after cooking for 30 minutes. But never dark brown.