You can turn this soupe à l’oignon, gratinée à la normande into an onion soup à la lyonnaise if you replace the cider with white wine. The flavours will just be a little different. My personal preference is for the sweet element that the cider brings, but the choice is yours. To make it suitable for vegetarians, simply replace the chicken stock with water.
SERVES 4
70g butter
400g onions, rinsed in cold water and finely sliced
250ml medium cider
1 small bouquet garni (thyme sprig, bay leaf and a few parsley stalks, tied together)
30g plain flour
650ml chicken stock
12–16 slices of baguette, cut at an angle, about 3mm thick
70ml double cream
30g Gruyère, mature Cheddar or Comté, grated
Sea salt and freshly ground pepper
Melt 40g of the butter in a fairly deep frying pan or sauté pan over a medium heat. Add the onions and sweat for 2 minutes, then increase the heat slightly and cook until lightly golden. Add 150ml of the cider and the bouquet garni and simmer for 5 minutes. Remove from the heat and set aside.
Melt the remaining 30g butter in a saucepan, add the flour and cook over a gentle heat for 2 minutes, stirring constantly with a whisk, to make a blond roux. Add the stock and bring to the boil, still stirring with the whisk. Cook over a gentle heat for 15 minutes.
Add the onion and cider mixture to the thickened stock and simmer for another 15 minutes, skimming the surface every few minutes. Remove the bouquet garni and season the soup with salt and pepper to taste; keep hot.
Meanwhile, for the croûtes, preheat the grill to high or the oven to 180°C/Gas 4. Toast the slices of baguette under the hot grill or in the oven for a few minutes until golden on both sides. (If using the oven rather than the grill to gratinée the soup, increase the setting to 200°C/Gas 6.)
To serve, pour the remaining cider equally into 4 warmed ovenproof bowls, then divide the onion soup between them. Spoon the cream on top and lay the croûtes on the surface. Sprinkle with the Gruyère and place under the grill (or in the oven) for a few minutes until gratinéed. Serve at once, while piping hot.