French Onion Mac and Cheese.

This french onion mac and cheese is a decadent twist on macaroni and cheese plus french onion soup. Caramelized onions, gruyere cheese sauce, fresh thyme and pasta come together in this baked dream of a side dish!

Just when you thought mac and cheese couldn’t get any better… 

I present to you: french onion mac and cheese!

Deeply caramelized onions. Silky gruyere cheese sauce with lots of garlic and thyme. Tender noodles swimming in the velvety cheese and baked until perfect. 

Oh my word. How does something this delicious even exist?! 

I have french onion-ed many many things. Almost all the things. But never mac and cheese! Which seems absolutely wild considering if anything would benefit from a whole host of caramelized onions, noodles and cheese. 

Inquiring minds want to know: are you a mac and cheese-on-Thanksgiving family, or not? We are a no-mac family on Thanksgiving. It’s never been a dish we’ve served. I might have made a version once or twice right after I had Max, but it’s never been a staple on our (very) traditional Thanksgiving table.

However, I know for many of you that it is a staple! 

Since it’s not one of the classic dishes on our table, I feel like I can change it up. While my family may go crazy if I make flavored mashed potatoes or a different kind of vegetable, the mac and cheese is up for grabs. It means that I can experiment and serve something fancy and fun.

And ridiculously decadent and delicious. 

This is that once-a-year recipe. The indulgent side dish you share on a super special occasion!

This is how I make it!

I use one large pan. You can do this in a dutch oven – I like to use my large le creuset braiser. 

First, I make caramelized onions. This will take a long time. Like, over one hour. You don’t have to babysit the onions the entire time, but you do want to stir them often. Adding a few splashes of water off and on will help them not burn. 

Once the onions are caramelized, I transfer them to a dish. I use that same pan to make the cheese sauce! I use a combination of gruyere and parmesan cheeses.

At some point in between these two things, I cook the pasta. It’s easy, done and ready to go.

When the cheese sauce is ready, I add the pasta into it. Then I add the caramelized onions. Another big sprinkle of cheese on top. 

Finally, I finish things off with a big breadcrumb sprinkle and a few extra caramely onions on top.

Then it’s time to bake! 25 to 30 minutes in the oven is all you need. Bake it until bubbly and cheese and melty and oh my goodness.

There should be a french onion mac and cheese candle!

This is a crazy good side dish. Even a fun main dish with a big greens salad. And it serves many people, because it’s rich and decadent. Great for the holiday season!

Caramelly crispy onions on top are all mine!

French Onion Mac and Cheese

French Onion Mac and Cheese

Yield: 12 people

Prep Time: 2 hours hrs

Cook Time: 30 minutes mins

Total Time: 2 hours hrs 30 minutes mins

This french onion mac and cheese is a decadent twist on macaroni and cheese plus french onion soup. Caramelized onions, gruyere cheese sauce, fresh thyme and pasta come together in this baked dream of a side dish!

Print Recipe Pin Recipe

5 from 5 votes

Leave a Review »

Ingredients

• 3 tablespoons olive oil
• 4 large sweet onions, thinly sliced
• kosher salt and pepper
• 1 pound short cut pasta, cooked
• 3 tablespoons unsalted butter
• ¼ cup all-purpose flour
• 2 ½ cups milk
• ¼ teaspoon freshly ground nutmeg
• 12 ounces gruyere cheese, freshly grated
• 4 ounces parmesan cheese, freshly grated
• ⅓ cup seasoned bread crumbs
• fresh thyme, for serving

Instructions 

• Heat the olive oil in a large oven-safe skillet over medium-heat. Stir in the onions with a big pinch of salt. Cook over medium, stirring often, until the onions soften, about 10 to 15 minutes.
• Decrease the heat to low or medium-low. Cook the onions, stirring often, for about 60 to 90 minutes, until they are golden and caramelly. If at any time the onions start to burn, low the heat or add a few splashes of water to keep them hydrated.
• Preheat the oven to 375 degrees F. Boil the pasta according to the package directions.
• Once the onions are golden and caramelly, transfer them to a plate. (Note: if you’re really in a rush, you can add 1 teaspoon of sugar, honey, maple syrup, etc to speed along the caramelization process. Be sure to stir often and check on the progress!)
• Add the butter to the skillet. Once melted, add in the flour, whisking to create a roux. Cook for 2 to 3 minutes, until it becomes golden in color and starts to smell nutty. Slowly stream in the milk while stirring constantly. The mixture will begin to come together and thicken. Stir in the nutmeg.
• Stir in almost all of the cheese (reserve a bit for topping) until it is melted. Add in ¾ of the caramelized onions. Stir in the pasta. Toss it together over and over until it is combined.
• Top with the remaining cheese on top along with the remaining onions. Sprinkle with the bread crumbs. Bake for 25 to 30 minutes, or until golden and bubbly.
• Remove and sprinkle with fresh thyme. Serve!

Course: Main Course, Side Dish

Cuisine: American

Author: How Sweet Eats

Did you make this recipe?

Be sure to follow @howsweeteats on instagram and tag #howsweeteats. You can also post a photo of your recipe to our facebook page.
I appreciate you so much!

Best dish ever.