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Caramelized Onion Carbonara_MidPage@2x

Caramelized Onion Carbonara

This caramelized onion carbonara recipe is a vegetarian take on the Roman classic. While there is no guanciale in this dish, smoked shoyu adds a great meaty flavor.
4.24 from 13 votes
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Prep Time: 10 minutes
Cook Time: 45 minutes
Total Time: 55 minutes
Servings: 4
Calories: 629kcal


  • Wide sauté pan
  • Large pot
  • Whisk
  • Colander, if needed


  • 1 tablespoon butter
  • 1 tablespoon extra virgin olive oil
  • 2 yellow onions peeled and diced
  • 2 teaspoons sugar
  • 16 ounces spaghetti, rigatoni, or bucatini
  • 1–2 tablespoons smoked shoyu more to taste if desired
  • 4 egg yolks
  • 2 eggs
  • cup freshly grated parmesan plus more for serving
  • Freshly grated black pepper
  • Salt


Caramelize the onions:

  • In a wide sauté pan, heat the butter and extra virgin olive oil over medium heat until the butter is frothy and bubbly. Add the diced onion and cook, stirring regularly, until the onions deepen in color. Adjust the heat as necessary to prevent it from burning. About 15 minutes in, add the sugar and smoked shoyu and continue cooking the onions for an additional 15–20 minutes until fully caramelized and deep, golden brown. Season with salt. Turn off the heat.

Cook the pasta:

  • Bring a large pot of salted water to a boil. Add the pasta and cook until 1–2 minutes under al dente. Scoop out 1½ cups of pasta cooking water and drain the pasta. Note: depending on how you time it, you may be ready to cook the eggs right as the pasta finishes cooking, in which case, you can just use tongs to transfer the pasta straight from the water to the pot of caramelized onions. If you aren't ready, just drain the pasta first!

Prepare the egg mixture:

  • In a large bowl, combine the egg yolks, eggs, parmesan, and ground black pepper to taste. Whisk for 3–5 minutes until smooth and creamy. Set aside.

Temper the egg mixture and finish the carbonara:

  • Whisking constantly, pour half of the pasta cooking water into the bowl of eggs to temper the egg mixture.
  • Return the heat on the skillet of caramelized onions to medium-low. Add the cooked pasta and toss to coat with the onions.
  • Keeping the heat on low, slowly add the egg mixture, tossing regularly, until completely coated. Turn off the heat as soon as the sauce is coated, and the pasta is warmed through (about 1–2 minutes). If the sauce is quite thick, add more of the remaining pasta cooking water until the sauce reaches your desired consistency. It should be glossy and stick to the pasta! Taste and season with salt and more freshly ground pepper to taste.

To serve:

  • Immediately serve the carbonara in shallow pasta bowls and garnish with more parmesan and black pepper. Enjoy!


Calories: 629kcal | Carbohydrates: 93g | Protein: 24g | Fat: 17g | Sodium: 207mg | Fiber: 5g | Sugar: 8g | Vitamin C: 4mg
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