Photo of Spaghetti with Caramelized Onions by WW

Spaghetti with Caramelized Onions

Total Time
10 hr 10 min
10 min
10 hr
Sweet, rich, and gorgeously colored, caramelized onions turn simple dishes into something special. We’ve used them here as a topping for pasta, but they’re great alongside any grilled protein.


Uncooked onion(s)

5 large, sweet onions such as Texas Sweet or Vidalia (about 4 1/2 pounds, sliced

Extra virgin olive oil

2 Tbsp

Kosher salt

1¼ tsp

Bay leaf

1 leaf/leaves, large size

Uncooked pasta

12 oz, preferably spaghetti

Black pepper

¼ tsp

Grated Parmesan cheese

12 Tbsp, or shaved


  1. Mix together onions, oil, and 1/2 teaspoon salt in 5- or 6-quart slow cooker. Tuck in bay leaf. Cover and cook until onions are golden and softened, about 6 hours on Low.
  2. Stir onions. Partially cover and cook, stirring once or twice, until onions are golden brown and most of liquid is evaporated, 4–5 hours on High. Stir in remaining 3/4 teaspoon salt. Remove and discard bay leaf.
  3. Meanwhile, cook spaghetti according to package directions. Drain and cover to keep warm.
  4. Divide pasta evenly among 6 large shallow bowls and top with onion mixture. Sprinkle with pepper, Parmesan, and thyme, if using.
  5. Per serving: about 1/2 cup onion, 1 cup pasta, and 2 tablespoons cheese.


Make an extra batch of these versatile and delicious caramelized onions to enjoy on top of burgers, tucked into omelettes, or layered into your favorite sandwich.