French Onion Soup
Is there such a thing as “light” French onion soup? The answer is an herbaceous, brothy bowl served to Chris Kimball at Bichettes in Paris. OR In Paris, we learned to make a light, bright French onion soup—the opposite of beef stock, soggy bread, and thick slab of cheese.
- Makes4 servings
- Cook Time1¾ hours
- 4
At Bichettes in Paris, chef Hortense Thireau prepares a French onion soup that is brighter and more herbaceous than typical versions. She caramelizes the onions less aggressively, deglazes only once with white wine, and swaps chicken stock for the typical beef stock—all tricks to keep things light. Additionally, rather than top her soup with bread, which becomes heavy as it soaks up broth, Thireau seals each bowl with a puff pastry lid. In the oven, the cheese-topped pastry crisps as it turns golden brown. Crock-like oven-safe bowls, each with a 12-ounce capacity, are best, but it’s possible to make this recipe without ovenproof bowls. In that case, while the onions caramelize, bake the egg-washed, cheese-sprinkled pastry rounds on a parchment-lined baking sheet for 25 to 30 minutes. Once the soup is portioned, simply top each bowl with a baked pastry round, or serve them alongside for dipping. Dufour frozen puff pastry is the hands-down best choice for this. Pure butter gives it a rich, sweet flavor, and it bakes up with a satisfying, almost bready texture. If Pepperidge Farm frozen puff pastry is the only option, you’ll need just one sheet from a 17.3-ounce box. After thawing and unfolding, if the sheet is too small to yield four rounds that are slightly wider than the bowls, give it a few passes under a rolling pin so it’s just large enough (Dufour pastry will not need to be rolled out unless your bowls are very wide). Comté is a nutty, buttery cow’s milk cheese; Gruyère is an excellent substitute.
Don’t use a wide pot, such as a Dutch oven, as the greater surface area allows faster evaporation of moisture, which increases the likelihood of browning before the onions fully soften. Also, stir the onions more often as they begin to color to prevent the flavorful fond that forms on the bottom of the pot from scorching.
Step 1
In a large saucepan over medium, melt the butter. Stir in the onions, thyme, bay and ¾ teaspoon salt. Cover and cook, stirring only occasionally at the start then more often once browning begins, until the onions are lightly golden and deep browning has formed on the bottom of the pot, about 45 minutes.
Step 2
Meanwhile, heat the oven to 375°F with a rack in the middle position. Place four 12-ounce oven-safe bowls on a rimmed baking sheet and sprinkle ¼ cup cheese in each; set aside. Lightly flour a counter and unfold the thawed puff pastry onto it; dust the surface with flour. Using a paring knife, cut out four rounds from the pastry, each about ½ inch larger than the diameter of the bowls. Stack the pastry rounds on a large plate and refrigerate, uncovered, until ready to use.
Step 3
Uncover the pot and stir in the cornstarch. Add the vermouth and cook, scraping up the browned bits, until the mixture is homogeneous and thickened, about 2 minutes. Stir in the broth, 1 cup water and ¼ teaspoon pepper. Bring to a simmer and cook, uncovered and stirring occasionally, until lightly thickened, about 15 minutes. Off heat, remove and discard the bay. Taste and season with salt and pepper.
Step 4
Divide the soup evenly among the bowls. Working one at a time, brush a thin layer of egg yolk around the rim, then place a pastry round on top; gently press around the rim of the bowl to secure the pastry. Once all four bowls are lidded, brush the pastry rounds with the remaining yolk and sprinkle with the remaining cheese. Bake until the pastry is puffed and golden brown, 25 to 30 minutes. Serve right away.
