French Onion Bucatini

4 servings


1 hour 40 minutes

total time



4 tablespoons unsalted butter

2 tablespoon neutral cooking oil (such as canola oil)

4 large (12 ounces each) red onions, thinly sliced (about 10 cups)2 teaspoons kosher salt, divided1/4 cup dry sherry

1 tablespoon all-purpose flour2 cups unsalted beef or chicken broth

2 tablespoons Worcestershire sauce

1 teaspoon fish sauce

3/4 teaspoon black pepper4 (5-inch) thyme sprigs

1 (2 1/2-inch) fresh or dried bay leaf

2 ounces Parmigiano-Reggiano cheese, grated (about 1/2 cup packed)

2 ounces Gruyère cheese, shredded (about 1/2 cup)

1 (12-ounce) package bucatini pasta

Gruyère breadcrumbs

2 tablespoons unsalted butter3/4 cup panko (Japanese-style breadcrumbs)

2 teaspoons fresh thyme leaves, plus more for garnish

1 small garlic clove, grated with a Microplane grater (about 1/2 teaspoon)1/2 teaspoon kosher salt

1/2 teaspoon black pepper1 ounce Gruyère cheese, finely grated with a Microplane grater (about 2/3 cup), plus more for garnish


Prepare the Pasta: Heat butter and oil in a large Dutch oven over medium. Add onions and 1/2 teaspoon of the salt; stir onions until evenly coated in butter. Cover and cook, stirring occasionally, until onions begin to soften, about 10 minutes. Uncover, and continue cooking over medium, stirring occasionally and scraping browned bits from bottom of pan, until onions are deep golden brown, meltingly soft, and jammy, 50 minutes to 1 hour. Remove 1/2 cup of the caramelized onions, and place in a small bowl; set aside.

While onions cook, prepare the Gruyère Breadcrumbs: Melt butter in a large skillet over medium. Stir in panko, thyme, garlic, salt, and pepper. Cook, stirring constantly, until panko is toasted and golden brown, 4 to 5 minutes. Transfer panko mixture to a medium bowl; set aside to cool until ready to use.

When onions are nearly done caramelizing, bring a large pot of salted water to a boil; add pasta, and cook to al dente according to package directions. Drain pasta, reserving 1/2 cup cooking water.

Once onions are caramelized, stir in sherry, scraping bottom of Dutch oven to loosen and dissolve browned bits. Cook, stirring constantly, until sherry has evaporated and alcohol smell has dissipated, about 1 minute. Stir in flour until onions are evenly coated. Add broth, Worcestershire sauce, fish sauce, pepper, thyme, bay leaf, and remaining 1 1/2 teaspoons salt. Bring to a simmer, stirring often. Continue to simmer, stirring occasionally, until liquid is slightly reduced and thickened, about 5 minutes. Remove and discard thyme sprigs and bay leaf.

Remove Dutch oven from heat; gradually stir in Parmigiano-Reggiano and shredded Gruyère, one handful at a time, until cheeses are melted. Add drained pasta and 1/4 cup of the reserved cooking water; toss until well combined. Continue tossing until a glossy sauce forms that evenly coats pasta, gradually adding remaining 1/4 cup cooking water, 1 tablespoon at a time, if needed. Stir in reserved caramelized onions until evenly distributed.

Divide pasta evenly between 4 bowls. Stir grated Gruyère into Breadcrumbs, and sprinkle evenly over pasta. Garnish with additional thyme leaves and grated Gruyère. Serve immediately.


Add 1 pack of leeks to the onions. Don’t do the breadcrumbs. Instead of sherry use sherry vinegar, a bit scant 1/4 cup. Use colatura rather than fish sauce. Used dry thyme and bay leaf. Use Penzey’s chicken and beef bouillon vs stock. Double amount of Gruyère. Used whole wheat spaghetti instead of bucatini.


Serving Size



2827 kcal

Total Fat

164 g

Saturated Fat

81 g

Unsaturated Fat

0 g

Trans Fat



377 mg


9248 mg

Total Carbohydrate

241 g

Dietary Fiber

17 g

Total Sugars

38 g


99 g

4 servings


1 hour 40 minutes

total time
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