Slow cooker French onion soup
Eight onions cooked down slowly into deep brown sweetness with thyme and a splash of wine. Dark, rich and very easy.
- Time10 hrs 15
- LevelEasy
- Costabout £1.54 a head
Cost is worked out from Aldi and Tesco shelf prices in October 2026. Your shop and brands will differ.
Ingredients
Tick what you need to buy. It goes on your shopping list.
Method
- 1
Put the onions, olive oil and salt into the slow cooker and stir so every slice is coated.
- 2
Cover and cook on low for 8 hours, stirring once if you are home, until the onions are very soft and a deep golden brown.
480 min - 3
Stir in the garlic and thyme. Pour in the wine and cook on high with the lid off for 20 minutes to cook off the alcohol.
20 min - 4
Add the stock, bay leaves, balsamic vinegar and pepper. Cover and cook on high for 1 hour.
60 min - 5
Remove the bay leaves, taste and adjust the salt. Ladle into bowls and serve with toasted bread.
Double check before you cook. Recipes can contain mistakes. Any diet labels come from the ingredients as written in this recipe and are a guide, not a guarantee. Always check every ingredient and the packet label for allergens and cross contamination, and ask your doctor or dietitian what is right for you, especially with coeliac disease, diabetes or a serious allergy. This is not medical advice.