Instant Pot French Onion Soup
Recipe Summary
A classic French onion soup prepared in the Instant Pot with quickly caramelized onions, rich beef broth, and aromatics, topped with crusty baguette slices and melted Gruyère cheese under the broiler.
Ingredients
| Ingredient | Amount | Notes |
|---|---|---|
| Yellow or sweet onions | 1–1.5 kg | Thinly sliced |
| Butter | 4 tbsp | |
| Garlic | 2 cloves | Minced |
| Beef broth | 1.5–2 liters | Rich quality |
| Dry red or white wine | 1/2 cup | Optional (or extra beef broth) |
| Worcestershire sauce | 1 tbsp | |
| Bay leaf | 1 | |
| Dried thyme | 1/2 tsp | |
| Baking soda | 1/2 tsp | Accelerates caramelization |
| Salt | To taste | |
| Black pepper | To taste | Freshly ground |
| Baguette | As needed | Sliced and toasted (for topping) |
| Gruyère or Swiss cheese | As needed | Grated (for topping) |
Instructions
-
Caramelize the Onions
Set the Instant Pot to “Sauté” mode and melt the butter (4 tbsp). Add the thinly sliced onions (1–1.5 kg) and sprinkle with baking soda (1/2 tsp). Sauté the onions, stirring occasionally, for 15–20 minutes until they turn a deep caramel brown.
-
Garlic and Deglazing
Add the minced garlic (2 cloves) and cook for 1 minute more. Pour in the wine (1/2 cup, optional) or a splash of beef broth, and scrape up all the caramelized browned bits (fond) stuck to the bottom of the pot with a wooden spatula.
-
Add Broth and Seasonings
Add the beef broth (1.5–2 L), Worcestershire sauce (1 tbsp), dried thyme (1/2 tsp), bay leaf (1), salt, and black pepper.
-
Pressure Cook
Close the lid and ensure the steam valve is set to “Sealing”. Cook on “Pressure Cook / Manual” on High pressure for 6–10 minutes.
-
Quick Release
When the cooking time is up, carefully perform a quick pressure release (Quick Release). Open the lid and discard the bay leaf. Taste and adjust seasoning with additional salt and pepper if needed.
-
Broil and Serve
Ladle the soup into oven-safe bowls. Place lightly toasted baguette slices on top and cover generously with grated Gruyère cheese. Broil in the oven for 3–5 minutes until the cheese is melted and bubbly with golden-brown spots. Serve immediately.
Useful Notes
Thickening & Bread Preparation
- Thickening: For a thicker soup, stir 1 tablespoon of all-purpose flour into the caramelized onions and cook for 1–2 minutes before adding the broth.
- Bread Preparation: Lightly toasting or drying the baguette slices in the oven beforehand prevents them from getting soggy too quickly and sinking under the cheese.
Role of Baking Soda
The 1/2 teaspoon of baking soda raises the pH of the onions, dramatically accelerating the Maillard caramelization process and helping achieve deep flavor in a fraction of the time.