Go Back

French Onion Soup Pasta

A cozy, cheesy pasta bake inspired by the rich flavors of French onion soup featuring caramelized onions, creamy béchamel sauce, and a crispy herby breadcrumb topping.
Print Recipe Pin Recipe
Prep Time 15 minutes
Cook Time 55 minutes
Total Time 1 hour 10 minutes
Servings: 6 servings
Course: Casserole, Dinner, Main Course
Cuisine: American, French-Inspired
Calories: 580
Ingredients Equipment Method Notes

Ingredients
  

For the Pasta and Sauce
  • 5 medium onions thinly sliced into long strips
  • 2 tbsp olive oil
  • 1 tsp sugar to speed caramelization
  • 2 cups beef broth
  • 2 tbsp unsalted butter for béchamel
  • 1 tbsp all-purpose flour to thicken sauce
  • 1.5 cups heavy cream
  • 1/4 cup ice-cold water to smooth sauce if needed
  • 2/3 cup caramelized onions from above
  • 1 tsp salt
  • 1/2 tsp garlic powder
  • 1/2 tsp smoked paprika
  • 1/8 tsp nutmeg
  • 2 tbsp fresh parsley chopped
  • 1/2 cup Parmesan cheese grated
  • 12 oz cavatappi pasta
For the Breadcrumb Topping
  • 1/2 baguette baguette torn into chunks
  • 1 tbsp olive oil
  • 1/2 tsp salt
  • 1/4 tsp black pepper
  • 1/2 tsp dried oregano can be swapped with thyme or rosemary

Equipment

  • Large Skillet
  • Large Pot
  • Food Processor
  • Baking Dish

Method
 

  1. Step 1: Preheat your oven to 350°F (175°C).
  2. Step 2: Slice onions thinly into long strips.
  3. Step 3: Heat olive oil in a large skillet over medium heat. Add sliced onions and cook, stirring occasionally, for 30–40 minutes until deeply golden brown. Sprinkle in sugar to speed caramelization if desired.
  4. Step 4: Add beef broth to the onions if they start to stick or dry out. Simmer for about 10 minutes, then remove from heat and set caramelized onions aside.
  5. Step 5: In the same skillet, melt butter over low to medium heat. Whisk in flour and cook for about 1 minute to remove raw flour taste.
  6. Step 6: Slowly add heavy cream while whisking constantly to thicken sauce. If lumps form, whisk in ice-cold water vigorously.
  7. Step 7: Stir in two-thirds of caramelized onions, salt, garlic powder, smoked paprika, nutmeg, chopped parsley, and Parmesan cheese. Simmer briefly to meld flavors.
  8. Step 8: Cook cavatappi pasta in salted boiling water until just before al dente. Drain well.
  9. Step 9: Toss cooked pasta with creamy onion sauce until evenly coated.
  10. Step 10: Prepare breadcrumbs by pulsing baguette chunks with olive oil, salt, pepper, and oregano in a food processor until coarse crumbs form.
  11. Step 11: Transfer pasta mixture to a baking dish. Spread remaining caramelized onions on top, then sprinkle breadcrumb topping evenly over.
  12. Step 12: Bake uncovered for 10–15 minutes until the top is golden brown and crispy.
  13. Step 13: Serve immediately while topping is crunchy and pasta is warm and creamy.

Notes

Feel free to swap beef broth for vegetable or mushroom broth for a vegetarian version. Use half-and-half instead of heavy cream for a lighter sauce. Add Gruyère, Swiss, or sharp cheddar cheese for a twist. Sauté mushrooms or spinach with the onions for extra veggies. Breadcrumb herbs can be changed to thyme or rosemary. Store leftovers refrigerated up to 3 days or freeze for up to 2 months. Reheat gently with broth or cream to restore creaminess.