Slow Cooker French Onion Soup

by Becca
2 people
9 hr 15 min

Let your appliance do all the hard work to make this spectacular slow cooker French onion soup! It’s rich and flavourful, and topped with a giant cheesy crouton.

If you like it when your dinner cooks itself, you’ll love this slow cooker French onion soup. It’s rich and earthy, sweet and tangy, and all-round wonderful. Add a super cheesy crouton, and you may as well just marry it now.

Slow cooker soup

I’m so excited to get my slow cooker out of the cupboard, now that the weather’s cooling off. There’s nothing better than an appliance that takes a job off my hands (notable mention to my other best buddy, the dishwasher).

A slow cooker is the perfect low effort appliance. Just chuck in a few raw ingredients (which in this case literally took me about 8 minutes), leave it to cook throughout the day, and dinner’s made itself. Hurrah!

Soup is the perfect thing to make in a slow cooker, as whatever you add has plenty of time to cook down beautifully, intensifying the flavours. Often, the amount of time you cook soup for isn’t hugely important, so if you’re not quite ready to eat when the soup’s ready, it probably won’t mind simmering away for another hour or two, until you’re hungry.

Slow Cooker French Onion Soup
Recipe details
  • 2  people
  • Prep time: 15 Minutes Cook time: 9 Hours Total time: 9 hr 15 min
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For the slow cooker French onion soup:
  • 4 large onions sliced
  • 30 g (~ 2 tbsp) butter, roughly chopped
  • 1 tbsp caster sugar
  • 1 tbsp balsamic vinegar
  • 2 tsp minced garlic or garlic puree
  • 1 tsp dried thyme
  • 1 tsp black pepper
  • 750 ml (~ 3 cups) vegetable stock
For the cheesy crouton:
  • 2-4 thick slices French baguette
  • 2-4 tbsp grated cheese (I used cheddar)

Add all of the soup ingredients to a slow cooker, and mix well to break up the onions. Cook on high for approximately 9 hours, or until the onions are a deep, rich brown colour, and very soft.
Serve on its own, or with a cheesy crouton. To make the cheesy crouton, dish up a bowlful of soup into a heat-safe bowl, and top with 1 or 2 thick slices of French baguette. Sprinkle over plenty of grated cheese, then place under a grill (broiler) for a few minutes, until the cheese is melted and slightly crispy. Serve immediately.
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