- 50g butter
- 650g onions, finely sliced
- 1 clove garlic, crushed
- 2tsp plain flour
- 175ml dry white wine
- 1litre hot beef stock
- 1 tbsp brandy (optional)
- 3/4 tsp salt
- For the Gruyère croutes:
- 50g Gruyère cheese, grated plus 1tbsp to sprinkle
- 2tsp Dijon mustard
- 4 x 3cm slices cut from a French baguette
- In a large heavy-based pan or casserole gently melt the butter over a low-medium heat then add the onions and stir well to coat. Cook for an hour on a low heat, covered but stirring occasionally until the onions are incredibly soft. Turn the heat up and cook uncovered for a further 15 minutes, until the moisture in the pan has evaporated and the onions have caramelised to a light golden brown colour. Add the garlic for the final 10 minutes of cooking.
- Add the flour to the pan and cook for 3 minutes constantly scrapping the bottom of the pan then add the wine stirring for another 3 minutes until reduced. Pour in the stock and leave to simmer very gently for 30 minutes adding the brandy for the final 5 minutes if using. Stir through the salt and allow the flavours to come together whilst making the croutes.
- Preheat the grill to high. Mix the cheese with the mustard then spread on the baguette slices and grill until the cheese is bubbling. Serve the warm soup in tureen bowls, float a cheese croute on top of each and sprinkle with the remaining cheese.