Melt the butter in a large pan and gently fry the onion over a very low heat, stirring frequently, until very soft and golden brown (about 30min). Add the garlic and flour and cook for a further 1min, stirring, continuously.
Step 2
Pour in the wine, bring to the boil and bubble until the wine is reduced in volume by half. Add the stock, then tie the bay leaf, thyme and parsley sprigs together with a piece of string to make a bouquet garni and add to the pan with some seasoning. Bring to the boil then carefully transfer mixture to a slow cooker, cover and cook on Low for 3-4hr until the onions are meltingly tender.
Step 3
When ready to serve, preheat the grill to medium. Lightly toast the slices of baguette on both sides. Reheat the soup and adjust the seasoning. Discard the bouquet garni.
Step 4
Divide the soup among four ovenproof soup bowls. Float two or three slices of toast on each portion and sprinkle thickly with the grated cheese. Stand the bowls under the hot grill until the cheese has melted and turned golden brown. Serve immediately.
An experienced and highly skilled team of food writers, stylists and digital content producers, the Good Housekeeping Cookery Team is a close-knit squad of food obsessives. Cookery Editor Emma Franklin is our resident chilli obsessive and barbecue expert, who spends an inordinate amount of time on holidays poking round the local supermarkets seeking out new and exciting foods. Senior Cookery Writer Alice Shields is a former pastry chef and baking fanatic who loves making bread and would have peanut butter with everything if she could. Her favourite carb is pasta, and our vibrant green spaghetti is her weeknight go-to. Lover of all things savoury, Senior Cookery Writer Grace Evans can be found eating crispy corn and nocellara olives at every opportunity, and will take the cheeseboard over dessert any time (though she cannot resist a slice of tres leches cake). With a wealth of professional kitchen know-how, culinary training and years of experience between them, they are all dedicated to ensuring every Good Housekeeping recipe is the best it can be, so you can trust they’ll work (and if they don’t – we’ll have the answer for why*) every time (*90% of the time the answer is: “buy an separate oven thermometer”!).
