French Onion Soup

French Onion Soup

This wonderfully rich and comforting soup is vegan and gluten-free.  The croutes are not vegan, but are well worth making if you can eat cheese.  The soup takes about 2½ hours to make, but it’s wonderful for a winter afternoon if you have other delights to prepare.  This recipe serves 8.


6 very large onions
Light oil as required (or you can use olive oil, to taste)
¼ tsp sea salt
2 quarts stock (use vegetable stock if serving to vegetarians), prewarmed
2 tsp potato starch or cornflour
3 fl oz dry white vermouth
salt and freshly ground pepper to taste

Croutes (optional)

25g butter, melted, plus extra for greasing (or goose fat, if you have any to hand)
½ small, day-old baguette, cut into cubes
½ garlic clove, peeled and halved
4 oz Gruyère, grated


1.   Peel, halve, and slice the onions very finely. Melt 30g butter in a very large, heavy-based lidded pan over a low heat.  (I use my largest Le Creuset casserole.). Add the onions.  Cover and sweat very gently, stirring occasionally, for 30 minutes.  Uncover, turn up the heat, sprinkle in the sugar and ¼ tsp salt.

2.   Continue cooking over medium-low heat for 1½ hours, stirring regularly, until the onions are tender, golden brown and quite dry.  Be alert – there will be a moment when the onions start to catch on the bottom;  when that happens, stir and push at the fond until it is mixed into the browning onions.

3.   Add the vermouth and let it boil up. Then add the warmed broth/stock, and stir.  Mix the cornflour or potato starch in a little water, and drip into the hot broth, stirring as it thickens.  Simmer very gently over low heat, with the cover askew, for at least an hour.

4.   Half an hour before serving, make the croutes. Rub the outside of the baguette with the cut garlic clove. Cut into 8 slices and lay closely together on a buttered baking sheet. Fry the slices until golden in the butter or goose fat. Sprinkle with most of the cheese, and bake for about 15 minutes until golden and bubbling.  Remove from the oven and leave to cool. When the cheese is hard and the bread crisp, carefully separate the slices – they will be stuck to each other with the cheese.

5.   Taste the soup and adjust the seasonings. Heat the oven to its highest setting.  Ladle the soup into heatproof bowls and arrange the croutes on top.  Cover the croutes with the remaining cheese.  Bake until the cheese is bubbling and serve immediately.

In the unlikely event that you have any left over, this soup freezes very well (without the croutes, of course).

Here is the downloadable file:  French Onion Soup.