Name: Caramelized Onion Pasta Recipe
Prep time: 10 min
Cook time: 35 min
Total time: 45 min
Yield: 4 servings
Cuisine: Italian
Ingredients: 3 large yellow onions, thinly sliced; 3 tablespoon olive oil; 1 tablespoon unsalted butter; 3 garlic cloves, minced; 12 oz spaghetti or fettuccine; ½ teaspoon kosher salt (plus more for pasta water); ¼ teaspoon freshly cracked black pepper; ½ cup freshly grated Parmesan cheese (plus more for serving); ¼ cup pasta cooking water (reserved); 1 tablespoon chopped fresh parsley (optional, for garnish)

Hey y'all! If you're on the hunt for a comforting bowl of pasta packed with rich, sweet, umami flavor, this Caramelized Onion Pasta Recipe is calling your name. Silky onions slowly caramelized to perfection pair with al dente pasta and a kiss of garlic, making this dish absolutely irresistible for weeknights, romantic dinners, or when you just crave something cozy and satisfying. Let's get cooking!

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Why You'll Love This

Ultra-flavorful: Caramelized onions bring deep, sweet, and savory notes you won't forget.
Simple ingredients: Everything you need is likely in your pantry and fridge already.
Versatile: Dress it up for a dinner party or keep it simple for a quick meal.
Vegetarian-friendly: Perfect for meatless Mondays or any plant-based meal.
Make-ahead friendly: The caramelized onions can be prepared ahead and frozen!

Ingredients

3 large yellow onions, thinly sliced
3 tablespoon olive oil
1 tablespoon unsalted butter
3 garlic cloves, minced
12 oz spaghetti or fettuccine
½ teaspoon kosher salt (plus more for pasta water)
¼ teaspoon freshly cracked black pepper
½ cup freshly grated Parmesan cheese (plus more for serving)
¼ cup pasta cooking water (reserved)
1 tablespoon chopped fresh parsley (optional, for garnish)

Directions

Step 1: Caramelize the Onions

Heat olive oil and butter in a large skillet over medium-low heat.
Add sliced onions and salt, stirring to coat.
Cook onions slowly, stirring every few minutes, for 25-30 minutes until deep golden, soft, and sweet. (Don't rush; patience yields the best flavor!)

Step 2: Make the Pasta

While the onions caramelize, bring a large pot of salted water to a boil.
Cook spaghetti or fettuccine until just al dente according to package instructions. Reserve ¼ cup pasta water, then drain pasta.

Step 3: Finish the Sauce

When onions are caramelized, add minced garlic and cook for 1 minute until fragrant.
Add cooked pasta to the skillet with onions and garlic.
Toss to combine, then add pasta water and parmesan. Stir well so the cheese melts into a silky sauce.
Season with black pepper, taste, and add more salt if needed.
Serve immediately, topped with extra parmesan and parsley if desired.

Notes

For even better caramelization, use a heavy-bottomed skillet or cast iron pan.
If onions start to get too dark before they're soft, add a splash of water and lower the heat.
Don't skimp on the salt in your pasta water for the best flavor.

Variations

Mushroom & Onion: Add 1 cup sliced mushrooms during the last 10 minutes of onion caramelization.
Creamy: Stir in ¼ cup heavy cream with the parmesan for a richer sauce.
Protein boost: Top with grilled chicken or crispy bacon bits.

Required Equipment

Large skillet or sauté pan
Large pasta pot
Sharp chef's knife
Wooden spoon or spatula
Colander
Measuring cups and spoons

Storage Instructions

Leftover Caramelized Onion Pasta can be stored in an airtight container in the refrigerator for up to 3 days. Reheat gently in a skillet with a splash of water or broth to loosen the sauce. Freezing is not recommended as the pasta texture may become mushy.

Suggested Pairings & Serving Recommendations

Serve alongside a crisp green salad with lemon vinaigrette.
Add garlic bread or a rustic baguette for soaking up extra sauce.
Pair with a glass of chilled white wine, like Pinot Grigio or Sauvignon Blanc.

Pro Tips

Let onions cook low and slow for maximum sweetness—don't rush!
Grate parmesan fresh for the best melt and flavor.
Use a splash of reserved pasta water for a glossy, clingy sauce.

FAQ

Can I make caramelized onions ahead of time?: Absolutely! Cook onions in advance and refrigerate for up to 4 days or freeze for up to 2 months.
What pasta works best for this recipe?: Spaghetti or fettuccine are great, but any long pasta (linguine, bucatini) will work well.
How do I make this vegan?: Swap butter for vegan margarine and use a dairy-free parmesan alternative.

Prep Time: 10 minutes
Cook Time: 30 minutes
Total Time: 40 minutes
Servings: 4