Slow-cooker French onion soup

Prep 30 min
Total 7 hours 30 min
Serves 4

This is one of our favourite comfort foods, and preparing it in the slow cooker makes it that much easier. For a stovetop version, caramelize the onions and salt over medium until dark golden. Add flour, then vermouth, broth and water, and simmer, covered, for at least 30 min.



1.75 kg
cooking onions, thinly sliced (about 14 cups)
3 tbsp
butter, cubed
1/4 tsp
4 1/2 tsp
all-purpose flour
3 tbsp
vermouth, or dry white wine
900-mL carton
1/3 cup
1 tbsp
butter, at room temperature
2 cups
grated gruyere or emmental cheese


  • COMBINE onions with butter and salt in slow cooker insert. Season with fresh pepper. Cover and cook on high until onions are soft and dark brown, about 6 hours.
  • STIR in flour until well combined. Stir in vermouth. Scrape up brown bits from bottom. Add broth and water. Cover and continue cooking on high for 1 1/2 hours.
  • POSITION rack in top third of oven. Preheat broiler. Cut bread into 8 slices, each 1/2 in. thick. Butter both sides and place on a baking sheet. Broil until lightly golden, about 1 min per side.
  • ARRANGE 4 oven-safe soup bowls on a baking sheet. Ladle soup into bowls. Top each with 2 toasts. Sprinkle with cheese. Broil until cheese is bubbly, 2 to 4 min.
  • Make-ahead tip: Soup (without toasts) keeps well up to 3 days in the fridge or up to 2 months in the freezer. Flavour will improve as it sits.

Note: Our slow cooker recipes are developed with a 7 quart slow cooker.


Calories 587
Protein 26 g
Carbohydrates 56 g
Fat 30 g
Fibre 7 g
Sodium 1840 mg
Excellent source of Vitamin B6

Chatelaine Quickies: French onion macaroni and cheese

Issue: February 2015

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Photo credit: Slow-cooker french onion soup. (Photo, Roberto Caruso.)

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