French Onion Spaghetti
French Onion Spaghetti
Ingredients
For the Caramelized Onions
- 3 yellow onions, large, thinly sliced
- 2 tablespoons unsalted butter
- 1 tablespoon olive oil
- 1/2 teaspoon granulated sugar
- 1/2 teaspoon salt
- 1/4 teaspoon black pepper, freshly ground
For the Sauce
- 2 tablespoons all-purpose flour
- 1/2 cup dry white wine, such as Sauvignon Blanc or Pinot Grigio
- 3 cups beef broth, hot
- 1 teaspoon Worcestershire sauce
- 1/2 teaspoon fresh thyme, chopped
- 1 teaspoon Dijon mustard
For the Spaghetti
- 12 ounces spaghetti
- 1/2 cup Parmesan cheese, grated, plus more for serving
- 2 tablespoons fresh parsley, chopped, for garnish
Instructions
- 1
Begin by caramelizing the onions. In a large, heavy-bottomed pot or Dutch oven, melt the butter with the olive oil over medium-low heat. Add the thinly sliced onions, sugar, salt, and pepper. Stir to coat.
⏱️ 5 min
- 2
Cook the onions slowly, stirring occasionally, for 40-50 minutes, or until they are deeply golden brown and very soft. If they start to stick, add a tablespoon or two of water to deglaze the bottom of the pot. This slow cooking is crucial for developing their sweet flavor.
⏱️ 45 min
- 3
Once the onions are caramelized, sprinkle the flour over them and stir well. Cook for 1-2 minutes, stirring constantly, to cook out the raw flour taste.
⏱️ 2 min
- 4
Pour in the white wine and scrape up any browned bits from the bottom of the pot. Let it simmer for 2-3 minutes until the liquid has mostly evaporated.
⏱️ 3 min
- 5
Gradually whisk in the hot beef broth, then add the Worcestershire sauce, fresh thyme, and Dijon mustard. Bring the sauce to a gentle simmer and cook for 5-7 minutes, stirring occasionally, until it slightly thickens.
⏱️ 7 min
- 6
While the sauce simmers, cook the spaghetti according to package directions in a large pot of salted boiling water until al dente. Reserve 1 cup of the pasta cooking water before draining.
⏱️ 10 min
- 7
Add the drained spaghetti directly to the pot with the French onion sauce. Toss well to coat the pasta evenly. Stir in 1/2 cup of grated Parmesan cheese.
⏱️ 3 min
- 8
If the sauce seems too thick, add a splash or two of the reserved pasta cooking water until it reaches your desired consistency.
⏱️ 1 min
- 9
Serve the French onion spaghetti immediately, garnished with additional grated Parmesan cheese and fresh chopped parsley.
⏱️ 1 min
Kitchen Tools
Nutrition Facts (per serving)
French Onion Spaghetti
For the Caramelized Onions
- 3 yellow onions, large, thinly sliced
- 2 tablespoons unsalted butter
- 1 tablespoon olive oil
- 1/2 teaspoon granulated sugar
- 1/2 teaspoon salt
- 1/4 teaspoon black pepper, freshly ground
For the Sauce
- 2 tablespoons all-purpose flour
- 1/2 cup dry white wine, such as Sauvignon Blanc or Pinot Grigio
- 3 cups beef broth, hot
- 1 teaspoon Worcestershire sauce
- 1/2 teaspoon fresh thyme, chopped
- 1 teaspoon Dijon mustard
For the Spaghetti
- 12 ounces spaghetti
- 1/2 cup Parmesan cheese, grated, plus more for serving
- 2 tablespoons fresh parsley, chopped, for garnish
Instructions
- 1
Begin by caramelizing the onions. In a large, heavy-bottomed pot or Dutch oven, melt the butter with the olive oil over medium-low heat. Add the thinly sliced onions, sugar, salt, and pepper. Stir to coat.
⏱️ 5 min - 2
Cook the onions slowly, stirring occasionally, for 40-50 minutes, or until they are deeply golden brown and very soft. If they start to stick, add a tablespoon or two of water to deglaze the bottom of the pot. This slow cooking is crucial for developing their sweet flavor.
⏱️ 45 min - 3
Once the onions are caramelized, sprinkle the flour over them and stir well. Cook for 1-2 minutes, stirring constantly, to cook out the raw flour taste.
⏱️ 2 min - 4
Pour in the white wine and scrape up any browned bits from the bottom of the pot. Let it simmer for 2-3 minutes until the liquid has mostly evaporated.
⏱️ 3 min - 5
Gradually whisk in the hot beef broth, then add the Worcestershire sauce, fresh thyme, and Dijon mustard. Bring the sauce to a gentle simmer and cook for 5-7 minutes, stirring occasionally, until it slightly thickens.
⏱️ 7 min - 6
While the sauce simmers, cook the spaghetti according to package directions in a large pot of salted boiling water until al dente. Reserve 1 cup of the pasta cooking water before draining.
⏱️ 10 min - 7
Add the drained spaghetti directly to the pot with the French onion sauce. Toss well to coat the pasta evenly. Stir in 1/2 cup of grated Parmesan cheese.
⏱️ 3 min - 8
If the sauce seems too thick, add a splash or two of the reserved pasta cooking water until it reaches your desired consistency.
⏱️ 1 min - 9
Serve the French onion spaghetti immediately, garnished with additional grated Parmesan cheese and fresh chopped parsley.
⏱️ 1 min