Crock Pot French Onion Soup Recipe
Slow-cooked to perfection, this classic French Onion Soup offers layers of caramelized onion sweetness balanced with savory beef broth and topped with a bubbling, golden Gruyere crust. Every spoonful brings cozy warmth, making it the ultimate comfort in a bowl.
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Servings: 4
Ingredients
- 4 cups low-sodium beef broth 1 quart
- 3 pounds yellow onions thinly sliced (about 6 medium onions)
- 2 tablespoons unsalted butter melted
- 4 garlic cloves finely minced (approximately 4 teaspoons)
- 1 tablespoon fresh thyme leaves or 1 teaspoon dried thyme
- 1 ½ teaspoons kosher salt with more for seasoning to taste
- ¼ teaspoon ground black pepper
- ½ cup dry white wine such as Sauvignon Blanc
- 8-12 slices of French bread sliced ¼-inch thick
- 3 tablespoons olive oil
- ½ cup shredded Gruyere cheese
Instructions
- In a 6-quart slow cooker, place the melted butter, sliced onions, minced garlic, thyme, kosher salt, and black pepper. Cover and cook on the high setting for 5 to 7 hours. Stir occasionally to ensure even caramelization of the onions until they reach a golden, caramelized consistency.
- Once the onions are well-cooked, pour in the beef broth and white wine. Cover once again and continue cooking on high for an additional 30 minutes.
- While the soup finishes, prepare the bread. Position an oven rack about 6 inches from the broiler, then preheat the broiler. Arrange the French bread slices on a baking sheet, and lightly brush both sides with olive oil. Broil the bread for 2 to 3 minutes per side, closely monitoring and rotating the pan as needed to avoid burning. Remove the toasted slices from the oven.
- When the soup is done, ladle it evenly into 4 oven-safe bowls or ramekins. Top each serving with 2 or 3 slices of the toasted bread, and sprinkle about 2 tablespoons of shredded Gruyere cheese over each bowl.
- Place the filled bowls on a baking sheet, then broil for about 2 minutes until the cheese is melted, golden, and bubbling. Keep a close watch to prevent over-browning. Sprinkle each serving with a pinch of salt and black pepper, and serve piping hot.
Notes
- Substitutions: Use chicken or vegetable broth if needed; Swiss or Emmental cheese can replace Gruyere, but Gruyere is best.
- Storage: Refrigerate leftover soup (without toppings) in an airtight container for up to 4 days; store bread separately at room temperature.
- Reheating: Warm leftovers on the stovetop over medium-low or in the microwave, then top with bread and cheese and broil as directed.
- Freezing: Freeze soup in an airtight container for up to 6 months; thaw overnight in the refrigerator before reheating.