french onion soup
6 tablespoons unsalted butter
3 pounds yellow onions sliced ⅛ inch thick (about 4 to 5 large onions)
½ teaspoon baking soda
Kosher salt and freshly ground black pepper
½ cup dry sherry
2 quarts low-sodium chicken stock
2 sprigs thyme
1 bay leaf
1 teaspoon Asian fish sauce (optional)
1 teaspoon cider vinegar
8 bowl-size slices French bread, toasted until crisp
1 medium clove garlic
1 pound Gruyère cheese, grated
Freshly minced chives, for garnish
- Melt butter in instant pot over medium heat.
- Add onions and baking soda and stir to combine. Season with salt and pepper. Cook, stirring, until onions slightly soften and start to release liquid, about 3 minutes.
- Seal pressure cooker and heat to high pressure. Cook at high pressure for 20 minutes. Release pressure by allowing steam to vent, then remove lid.
- Continue cooking with lid off, stirring constantly, until liquid inside has completely reduced and the onions are deep brown and sticky, about 5 minutes.
- Add sherry and bring to a simmer, scraping up any browned bits. Cook until alcohol smell is mostly gone, about 3 minutes.
- Add stock, thyme, and bay leaf, raise heat to medium-high, and bring to a simmer. Lower heat and simmer for 10 minutes.
- Add fish sauce, if using, and cider vinegar and season with salt and pepper (if necessary). Discard thyme sprigs and bay leaf.
Serve with Gruyere Cheese Toast
- Preheat broiler and move oven rack to top position.
- Sprinkle some grated Gruyere on top of toasts
- Broil until cheese is melted and browned in spots.
- Add soup to bowls and top with toast.
- Garnish with chives and serve.