Baked French Onion Soup in the Slow Cooker


Onion Soup

This was the recipe I was dreading. The very first thing we cooked in our slow cooker back in 2009 was French Onion Soup. It was Tim’s request. We cooked it on a Saturday, and the rancid smell of boiling onions filled the house. For months afterwards, it seemed that the smell of boiled onions lingered around the slow cooker and around the house. That soup definitely wasn’t worth it.

This soup is very different. Same basic, simple ingredients – it’s a recipe that really celebrates the onions – but quite a different method, involving a cartouche of baking parchment over the onions for 5 hours before the stock is added. This time, there was no lingering malodor; just the sweet caramelised onions that you hope for.

The highlight is always the cheese-topped slices of baguette. Without them, really, you are just eating onions.


  • 500g onions, sliced into half-moons
  • 1 clove garlic, thinly sliced
  • 1 bay leaf
  • 1 tsp fresh thyme leaves
  • Olive oil
  • 250ml beef stock
  • 4 slices baguette
  • 60g gruyere cheese


  1. In a frying pan, saute the onions, garlic, bay leaf and thyme in the oil until the onions are softening and beginning to colour slightly.
  2. Transfer the mixture to the slow cooker.
  3. Create a cartouche of parchment by cutting a circle of baking parchment to fit your slow cooker. Make it wet under the tap, then tuck it over your onions.
  4. Cook on Low for 5-6 hours.
  5. Remove the lid, turn the heat up and cook on high for 20 minutes, stirring occasionally to colour the onions.
  6. Add the stock and season well. Cook for a further 40 minutes
  7. Before you eat, top the slices of baguette with the cheese and place under a hot grill until the cheese melts.
  8. Serve the soup in bowls with the baguette slices on top.

Screen Shot 2013-04-01 at 14.54.49

By Naomi

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