Roasted Onion Butter Fettuccine

The most decadent roasted onion butter fettuccine. Thick strands of fettuccine pasta tossed in a silky, richly flavored sauce with notes of garlic, sage, black pepper, and parmesan. The ingredients are minimal and the flavor is big. It’s the most comforting pasta side dish to add on to any fall or winter meal!

finished plate of roasted onion butter fettuccine

fettuccine being tossed in a skillet with the roasted onion butter

roasted onion butter fettuccine – the details

Infusing butter is a great way to get lots of flavor into a pasta dish, especially when you want to make a pasta that uses minimal ingredients and comes together quickly. I recently created a roasted onion butter with this in mind.

The butter is rich in flavor, with deeply roasted (slightly charred) onions being the focal point, and roasted garlic and herbs adding additional hints of savoriness. And when tossed with fettuccine? It’s pure indulgence.

finished plate of roasted onion butter fettuccine

The best part about this recipe is that the roasted onion butter can be made ahead of time. Maybe on a weekend when you have a few extra moments to play around in the kitchen.

Then, when the craving strikes, or when you simply need to get dinner on the table fast, you can whip up this fettuccine. The butter and some starchy pasta water create the sauce, black pepper is added for an extra kick, and plenty of parmesan cheese adds to the lusciousness of the fettuccine.

So simple, yet truly exquisite when it comes together.

finished plate of roasted onion butter fettuccine

My main recommendation is to use a microplane to freshly grate the parmesan cheese from a real block of Parmigiano Reggiano (compared to using pre-grated parmesan that typically contains additives). This will ensure the parmesan is light and delicate enough to easily melt into the sauce.


Roasted Onion Butter Fettuccine

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fettuccine pasta tossed in a roasted onion butter sauce with notes of garlic, sage, black pepper, and parmesan

servings: 4


  • ½ lb fettuccine
  • ½ cup roasted onion butter
  • freshly cracked black pepper
  • ½ cup freshly grated parmesan cheese, plus more for topping


  1. Bring a large pot of salted water to a boil. Drop the fettuccine into the water and stir well. Cook for 1 minute less than the package’s instructions.
  2. A few minutes before draining the pasta, heat a 12” stainless steel skillet over medium heat. Add a ½ cup of roasted onion butter, plus a few good cracks of black pepper. Allow the butter to melt.
  3. Retrieve 1 cup of pasta water from the pot (plus save a little extra on the side if needed) and add it to the skillet. Stir well and bring the sauce to a simmer. Simmer for a minute or so. Drain the pasta and add it directly to the sauce. Toss for 1 minute until the sauce clings to the pasta. Sprinkle in the grated parmesan, stirring until it’s incorporated.
  4. The sauce should be silky-smooth and generously coating the pasta. Add a little more pasta water if needed. Season with salt to taste. Plate the pasta with freshly cracked black pepper and more parmesan over top.

finished plate of roasted onion butter fettuccine

6 thoughts on “Roasted Onion Butter Fettuccine

    1. Hi Cristina! Thanks so much! I personally would make it without and eat it alongside roast chicken or a simply seared steak. For the holidays it’d be a great side to a beef roast, too! If you did want to add meat directly to it, shredded chicken would probably incorporate well. I hope this helps! -Kayla

  1. Just made this tonight and it’s by far the best thing we’ve had in a while, sooooo good, I had to stop myself from eating the sauce… giving this a 5 star!!!! Wow

  2. I save and make a lot of recipes, but it’s not often that I want to make it the minute I see it, but I want to make this NOW. And it’s breakfast time. Looking forward to trying it!

    1. Thanks Kristin! I feel the same way every time I look at the photos. It really is so good – I hope you absolutely love it!

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