Mary Berry’s French Onion Soup with Mustard Cheese Croûtes

1. Heat the butter and oil in a deep saucepan. When the butter has melted, add the onions and fry over a high heat for about 2–3 minutes. Lower the heat, cover with a lid and cook for about 10 minutes or until starting to soften.

2. Remove the lid, sprinkle in the sugar and season with salt and pepper, then fry over a high heat for 2–3 minutes, stirring. Reduce the heat to low and cook for 15 minutes, stirring occasionally, until the onions are tender, golden and caramelised.

3. Preheat the grill to medium-high.

4. Pour in the wine and boil for 2-3 minutes to allow the alcohol to evaporate. Add the stock and herbs, then bring back up to the boil and simmer over a medium-high heat for 8–10 minutes.

5. Meanwhile, make the croûtes. Slice the baguette into 6 thick or 12 thinner slices and toast one side under the grill. Spread the untoasted side with mustard and top with cheese. Pop under the grill for a few minutes to cook until just melted.

6. Remove the herbs from the soup, check the seasoning and serve in warmed bowls with the mustard cheese croûtes on top.

Prepare Ahead:

The soup can be made up to 4 days ahead. The croûtes can be assembled up to 8 hours ahead, then finished under the grill just before serving.

Mary’s Classic Tips:

* Leave the root on when slicing the onions. It holds the onion together and helps to reduce the inevitable tears!

* A homemade stock or fresh stock from the supermarket give the best flavour for this dish; if not, a concentrated stock pot would be preferable to a powdered cube. Beef stock is traditional but vegetable stock can be substituted for vegetarians.