Caramelized Onion Spaghetti: The Surprisingly Elegant Pasta You’ll Make on Repeat
This elegant Caramelized Onion Spaghetti transforms humble onions into sweet, jammy perfection that coats every strand of pasta with deep, complex flavor. With just 6 core ingredients and 40 minutes (mostly hands-off), you’ll have restaurant-quality pasta that tastes like you spent hours in the kitchen. The slow-caramelized onions provide incredible sweetness balanced by salty parmesan and buttery richness.
- Prep Time: 10 minutes
- Cook Time: 40 minutes
- Total Time: 50 minutes
- Yield: 4 servings
- Category: Main Dish, Pasta, Dinner
- Method: Stovetop, Caramelizing
- Cuisine: Italian, Italian,American
- Diet: Vegetarian
Ingredients
Core Ingredients:
- 1 pound spaghetti
- 4 large yellow onions (about 2 pounds), thinly sliced
- 4 tablespoons unsalted butter, divided
- 2 tablespoons olive oil
- 1 teaspoon salt, plus more for pasta water
- ½ teaspoon black pepper
- 1 cup freshly grated parmesan cheese (plus more for serving)
- Reserved pasta water (about 1 cup)
Optional Additions:
- Fresh thyme or sage
- 1 tablespoon balsamic vinegar
- ¼ cup dry white wine
- Toasted breadcrumbs
- Red pepper flakes
- Fresh parsley
Instructions
- Caramelize onions: Heat 2 tbsp butter and 2 tbsp olive oil in large skillet over medium heat. Add sliced onions, salt, and pepper. Cook, stirring every 5-7 minutes, for 30-40 minutes over medium-low heat until deep golden brown and very soft. Reduce heat if onions start to burn.
- Cook pasta: About 15 minutes before onions finish, bring large pot of heavily salted water to boil. Cook spaghetti until al dente (about 1 minute less than package directions). Reserve 1 cup pasta water before draining.
- Combine: Add remaining 2 tbsp butter to caramelized onions over medium heat. Add drained pasta and toss with tongs to coat. Add pasta water a few tablespoons at a time, tossing constantly, until sauce is silky and coats pasta (you may need ¼ to ¾ cup total).
- Finish: Remove from heat. Add ¾ cup parmesan and toss vigorously until cheese melts and creates creamy coating. Taste and adjust seasoning.
- Serve: Divide among warm bowls. Top with additional parmesan, black pepper, and optional garnishes. Serve immediately.
Notes
- Low and slow is essential—don’t rush the onion caramelization
- Yellow onions provide the best balance of sweetness and depth
- Reserve more pasta water than you think you’ll need
- Fresh parmesan melts better than pre-grated
- Add cheese off heat to prevent it from becoming grainy
- Pasta is best served immediately
- Can caramelize onions up to a week ahead and refrigerate
- Works with any long pasta shape
- For vegan version, use olive oil instead of butter and nutritional yeast/vegan parm instead of cheese
Find it online: https://recipya.com/caramelized-onion-spaghetti-recipe-7-tips/