French onion soup is a classic for a reason – it uses simple ingredients, yet is incredibly comforting and hearty. The onions are cooked slowly until almost caramelised, before being topped with a cheesy toast to mop up all those lovely flavours.
- Melt the butter and oil together in a large heavy-based pan over a medium heat. Add the onions and salt and cook for 10 mins, stirring regularly until softened. Reduce the heat to low and cover the pan with a lid. Cook for 15 mins, stirring occasionally.
- Add the garlic and cook, uncovered, for another 10-12 mins or until the onions are very soft and caramelised. Keep stirring every so often to stop them catching.
- Sprinkle in the flour and stir to mix well. Increase the heat and pour in the wine, if using, allowing it to bubble away for a few mins. Make up the stock cubes with 1 ltr hot water and add to the pan along with the thyme sprigs. Bring to the boil, then leave to simmer for 30 mins.
- Preheat the grill to high. Toast the baguette slices on each side. Ladle the soup into 4 heat-proof bowls or dishes and top each with 2 baguette slices. Scatter with the grated cheese then cook under the hot grill for 1-2 mins until the cheese is melted, bubbling and golden.
- Garnish with freshly ground black pepper and a few fresh thyme leaves to serve.
Tip: If you don’t have heat-proof bowls to serve, toast the baguettes as above, then place on a baking tray. Top with the cheese and place under the grill to melt, then ladle the soup into serving bowls and place the grilled cheese toasts on top.
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Freezing and defrosting guidelines
Freeze soup only. Cook to the end of step 3, then cool completely and transfer to a freezer-proof container, leaving a little room for expansion. Defrost fully at room temperature then transfer to a pan and heat through until bubbling. In order to enjoy optimum flavour and quality, frozen items are best used within 3 months of their freezing date. For more tips on freezing and defrosting food, read our article Love Your Freezer.