French Onion Mac Cheese Bake (Print Version)

Creamy mac and cheese meets caramelized onions in a baked, cheesy, and flavorful one-pot dish.

# What You'll Need:

→ Onions

01 - 3 large yellow onions, thinly sliced
02 - 2 tablespoons unsalted butter
03 - 1 tablespoon olive oil
04 - 1/2 teaspoon salt
05 - 1/2 teaspoon sugar

→ Pasta

06 - 14 ounces elbow macaroni or cavatappi

→ Liquids

07 - 4 cups low-sodium vegetable broth
08 - 1 cup whole milk

→ Cheeses

09 - 2 cups shredded Gruyère cheese
10 - 1 cup shredded sharp white cheddar cheese
11 - 1/2 cup grated Parmesan cheese

→ Seasonings

12 - 2 cloves garlic, minced
13 - 1/2 teaspoon dried thyme
14 - 1/2 teaspoon black pepper
15 - Salt to taste

→ Topping

16 - 1 cup fresh breadcrumbs
17 - 2 tablespoons unsalted butter, melted
18 - 2 tablespoons finely chopped parsley (optional)

# How-To Steps:

01 - Heat butter and olive oil in a large oven-safe pot over medium heat. Add sliced onions, salt, and sugar. Cook, stirring frequently, for 20 to 25 minutes until onions are deeply golden and caramelized.
02 - Stir in minced garlic and dried thyme, cooking for 1 minute until fragrant.
03 - Set the oven temperature to 400°F (200°C).
04 - Add dry pasta to the pot with onions. Pour in vegetable broth and milk. Stir thoroughly, scraping up any browned bits from the bottom.
05 - Bring to a simmer, cover, and cook over medium-low heat for 10 to 12 minutes, stirring occasionally, until pasta is just al dente and most liquid has been absorbed.
06 - Remove from heat. Stir in Gruyère, cheddar, and half of the Parmesan cheese until fully melted and the mixture is smooth. Adjust salt and pepper to taste.
07 - Combine fresh breadcrumbs with melted butter in a small bowl. Evenly sprinkle the mixture over the pasta, then top with the remaining Parmesan cheese.
08 - Place the pot uncovered in the preheated oven and bake for 10 to 15 minutes until the topping is golden and bubbling.
09 - Allow to rest for 5 minutes. Garnish with chopped parsley before serving, if desired.

# Expert Tips:

01 -
  • Combines beloved French onion soup flavors with creamy mac and cheese in one comforting bake.
  • Made in just one pot to minimize cleanup while maximizing flavor.
  • The caramelized onions add a deep, sweet-savory richness that elevates every bite.
  • A crispy, golden breadcrumb and Parmesan topping adds delightful texture contrast.
  • Vegetarian-friendly while still packing a cheesy, hearty punch.
02 -
  • Use a heavy-bottomed, oven-safe pot to evenly caramelize onions and bake the dish.
  • Scrape the browned bits from the pot when adding broth for extra flavor depth.
  • Keep an eye on the pasta while simmering to avoid overcooking; al dente texture is key.
  • Mix the cheeses before adding to ensure a smooth, even melt.
  • Toast the breadcrumbs lightly before mixing with butter for an extra crunchy topping.
Go Back