Simple Caramelized Onion Pasta Recipe

There's nothing quite like a simple and elegant pasta dish with well prepared ingredients — something the Italians know all too well. While pasta is often seen as a quick and convenient meal, easy to throw together on a busy weekday with sauce from a jar, it is definitely worthwhile to spend a bit more time and effort on making a meal you can be proud of.

Onions are used in plenty of dishes as a base ingredient for heaps of flavor, but they usually aren't the star of the show. This simple caramelized onion pasta recipe by Jennine Rye, on the other hand, turns this humble and often overlooked workhorse of an allium into the centerpiece of the dish. The lengthy process of caramelizing onions is well worth their resulting taste, and with rich butter, salty Parmesan, and perfectly al dente spaghetti, this dish is both deeply comforting and highly sophisticated. Whether you are looking for a new favorite pasta dish or an interesting meal to serve at a dinner party, this simple caramelized onion pasta is definitely one to consider.

Gather the ingredients for this simple caramelized onion pasta recipe

To begin this simple caramelized onion pasta recipe, first you will need to gather the ingredients. You will want white onions, olive oil, balsamic vinegar, brown sugar, spaghetti, butter, Parmesan, and salt and black pepper, to taste.

Step 1: Slice the onions

Slice onions into strips.

Step 2: Add the onions to a pan

Place a large pan over low heat and add the onions and olive oil.

Step 3: Caramelize the onions

Let the mixture slowly cook for 40 minutes, stirring occasionally as the onions caramelize.

Step 4: Add sugar and balsamic vinegar

After 40 minutes, when the onions are soft and browning, add balsamic vinegar and brown sugar.

Step 5: Finish cooking the onions

Cook for 5 more minutes and turn off the heat.

Step 6: Cook the spaghetti

Add spaghetti to a large saucepan of salted boiling water and cook according to package instructions until al dente.

Step 7: Drain the spaghetti

Reserve 1 cup pasta cooking water before draining the spaghetti.

Step 8: Add the spaghetti to the onions

Add spaghetti to the pan of caramelized onions along with the butter, Parmesan, and a few splashes of pasta water. Stir well to form a sauce.

Step 9: Taste for seasoning, and serve

Season well with salt and pepper before serving.

How can I change up this simple caramelized onion pasta?

Caramelized onions are undeniably delicious. They also take a pretty long time to make, and there aren't really any shortcuts that will result in the same flavor for this dish. However, some supermarkets do serve packets of pre-caramelized onions if you are looking for a way to enjoy this dish without the lengthy caramelization process. The packaged version won't taste exactly the same, but it will definitely still give you that sticky sweetness for which caramelized onions are prized.

This recipe can be adapted in a variety of other ways depending on your desires and personal preferences. The spaghetti can easily be substituted for another pasta shape, or the whole dish can be made gluten-free with a simple swap to gluten-free pasta. To make the dish dairy-free, you will want to swap out the butter for a dairy-free variety, and you can either omit the Parmesan or use a dairy-free alternative.

While this dish is delicious as it is, you can also bulk it out with more ingredients if you are looking to enjoy a more substantial meal. Chicken or sausage pair well with the sweetness of the caramelized onions; they can be cooked separately and then stirred into the final dish. Mushrooms also make a great vegetarian addition to this dish.

What pairs well with caramelized onion pasta?

This simple caramelized onion pasta recipe can be served in a variety of ways, depending on the occasion and your personal preferences. Like pasta alfredo or spaghetti carbonara, we think this dish is ideal when enjoyed as a standalone dish. The onions, butter, and Parmesan give this recipe more than enough savory flavor and silky texture to provide an interesting and delicious meal option all by itself. To add a little freshness, a side salad of mixed leaves dressed with a simple vinaigrette would make a perfect accompaniment, adding a little lightness to the dinner.

If you are looking for a little more, however, this pasta dish is delicious alongside steak, pork, chicken, or your protein of choice. For a vegetarian side option, grilled and stuffed portobello mushrooms pair wonderfully with the caramelized onions. And to finish off the dish, why not top the spaghetti with a little more Parmesan, some toasted pine nuts, fresh chopped herbs, or deliciously crunchy flavored breadcrumbs? For wine pairings, we recommend sticking with a light and crisp chilled white wine.

Simple Caramelized Onion Pasta Recipe
5 from 35 ratings
Caramelizing onions is well worth it for the buttery, deeply umami results of this simple yet sophisticated pasta dinner.
Prep Time
10
minutes
Cook Time
1
hour
Servings
4
servings
caramelized onion pasta in pan with spoon
Total time: 1 hour, 10 minutes
Ingredients
  • 3 medium white onions
  • 2 tablespoons olive oil
  • 1 tablespoon balsamic vinegar
  • 1 tablespoon brown sugar
  • 12 ounces spaghetti
  • 2 tablespoons butter
  • ⅓ cup grated Parmesan, plus more for serving
  • Salt and black pepper, to taste
Directions
  1. Slice onions into strips.
  2. Place a large pan over low heat and add the onions and olive oil.
  3. Let the mixture slowly cook for 40 minutes, stirring occasionally as the onions caramelize.
  4. After 40 minutes, when the onions are soft and browning, add balsamic vinegar and brown sugar.
  5. Cook for 5 more minutes and turn off the heat.
  6. Add spaghetti to a large saucepan of salted boiling water and cook according to package instructions until al dente.
  7. Reserve 1 cup pasta cooking water before draining the spaghetti.
  8. Add spaghetti to the pan of caramelized onions along with the butter, Parmesan, and a few splashes of pasta water. Stir well to form a sauce.
  9. Season well with salt and pepper before serving.
Nutrition
Calories per Serving 521
Total Fat 17.0 g
Saturated Fat 6.6 g
Trans Fat 0.0 g
Cholesterol 23.7 mg
Total Carbohydrates 74.9 g
Dietary Fiber 4.3 g
Total Sugars 8.6 g
Sodium 466.6 mg
Protein 16.5 g
The information shown is Edamam’s estimate based on available ingredients and preparation. It should not be considered a substitute for a professional nutritionist’s advice.
Rate this recipe