This French Onion Mac and Cheese is the cozy pasta bake you didn’t know you needed, sweet caramelized onions, smoky crispy bacon, and a creamy Gruyère cheese sauce all baked under a golden, buttery panko topping. It’s rich, comforting, and bursting with big flavor. The kind of dish everyone goes back for seconds of.
This French onion mac and cheese recipe is my grown up twist on the classic. It still has all the creamy, cheesy comfort you want, but the sweet caramelized onions and smoky bacon take it to another level. It’s the kind of side that completely steals the show at Thanksgiving or any holiday table, and honestly it blows people away every time I serve it.
If you love a baked pasta situation, you’re in the right place. Try my Mac and Cheese with Leeks and Bacon, my Gouda Mac and Cheese, or my Sausage Pasta Bake next. They all follow that same cozy, golden topped vibe that everybody adores.
Main ingredients
Pasta - Any short pasta works, but shapes with ridges or cavities like pipe rigate, elbows, or macaroni are best.
Onions - I used 5 yellow onions but ours are much smaller where I live, that is why I have given an overall weight of 850 grams. It might be more like 3 where you live.
Balsamic glaze - I finish off the caramelized onions with a thick balsamic glaze. It's easy to find in a grocery store. You can leave it out if you wish but it gives a fantastic flavor.
Bacon - You could substitute for pancetta.
Panko breadcrumbs - These are a type of Japanese breadcrumb that are really easy to find in a grocery store.
Milk - Whole milk gives the creamiest texture and I have not tested this with anything else.
Cheese - You can use a mix, I used gruyere, cheddar and mozzarella. Gruyere gives a wonderful flavor so I highly recommend including it.
Rosemary - I use fresh rosemary in the topping, you can substitute with thyme.
How to make French Onion Mac and Cheese
You can find the full ingredient list and method in the bottom of the post, this is just a visual overview.
Caramelizing the onions
ONE: This is the onions before. Use a large skillet, Dutch oven or any oven proof casserole dish.
TWO: After 45 minutes and the balsamic glaze added.
Making the sauce and assembling
ONE: Add the butter to the skillet and when sizzling follow with the flour to make a paste. Cook off for a minute.
TWO: Add the milk slowly, whisking and incorporating the flour mixture from the bottom of the pan into a smooth liquid. After 4-5 minutes it will thicken to coat the back of a wooden spoon.
THREE: Turn off the heat and add the cheese in three separate lots, letting it melt in between each addition.
FOUR: Add in the cooked pasta, bacon, half the onions and mix well.
FIVE: Layer the remaining onions on top.
SIX: Sprinkle the panko crumbs on top and bake at 350f for 25 minutes.
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Some tips for success
- Caramelize the onions low and slow - don’t rush this step, deep golden onions give the dish its signature flavor.
- Undercook your pasta - No one likes a mushy mac and cheese and it will never happen if you undercook your dried pasta by 2 minutes from package instructions.
- Grate the cheese yourself - pre-shredded cheese contains anti-caking agents that stop the cheese melting smoothly into a sauce.
Some other pasta bakes to try
If you love French onion mac and cheese then make sure you check out all my cozy pasta bake recipes! Here are a few suggestions:
Did you make this recipe?
I would LOVE it if you could leave a review and star rating down below. Also please tag me on Instagram if you share a photo of the dish!
Recipe
Caramelized Onion Mac and Cheese
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Ingredients
- 300 grams pasta I used pipe rigate
- ½ tablespoon olive oil
- 250 grams bacon cut into small pieces
For the onions
- 1 tablespoon olive oil
- 1 tablespoon butter (or use 2 tbsp oil)
- 4 - 5 small onions (my 5 were 850 grams in total before cut)
- ½ teaspoon salt
- 1.5 tablespoons balsamic glaze
For the panko topping
- 1.5 cups panko breadcrumbs
- 70 grams butter melted
- 1 tablespoon fresh rosemary leaves roughly chopped
- 1 zest of a small lemon (optional)
For the cheese sauce
- 70 grams butter
- 60 grams plain flour (½ cup)
- 900 mls milk (approx 3 ¾ cups)
- 350 grams cheese (I used a split of gruyere, mozzarella and Parmesan but see notes for details)
- 1 teaspoon black pepper
- 1 teaspoon salt
Instructions
For the caramelized onions
- Get the onions going first, they take the longest. While they cook you can boil the pasta, make the topping and fry the bacon.
- Trim both ends off the onions then cut in half lengthways, peel, then lay each half flat and slice into ¼-inch thick half circles
- Heat 1 tablespoon of olive oil and 1 tablespoon of butter in a heavy bottomed skillet or Dutch oven over a medium heat and cook the onions for 10 minutes until softened.
- Mix the salt through then lower the heat down to low and continue cooking for 40 minutes until golden and super soft. It needs to be stirred often so they don't catch and burn. The video below will really help!
- Add the balsamic glaze, mix well and continue cooking for five minutes then set aside.
For the pasta
- Boil your pasta, undercooking by 2 minutes from package instructions. Drain and then toss with a knob of butter to stop it sticking and overcooking.
For the panko topping
- Melt the butter and mix with the panko crumbs, rosemary and lemon zest and set aside.
Fry the bacon
- Heat ½ tablespoon of olive oil in large skillet and fry the bacon until crisp and golden, about 10 minutes.
- Set aside.
For the sauce
- Preheat your oven to 350f (180c).
- Make the cheese sauce in a large oven-proof skillet (I used a 32cm Le Creuset shallow casserole), or make it in a saucepan and mix everything together before transferring to a casserole dish to bake.
- Heat the butter over a medium heat and when sizzling, add the flour.
- Whisk or mix vigorously for a minute to cook the flour off.
- Lower the heat and add half of the milk in a slow stream, whisking the whole time and making sure you are getting all the flour mixture from the bottom and sides of the pan.
- Once all the flour mixture is incorporated add the rest of the milk and whisk really well. I often add the milk a cup at a time.
- Cook for 4-5 minutes, stirring until it thickens and coats the back of a wooden spoon. It should never be boiling.
- Remove from the heat and add the cheese in three separate lots, whisking and letting it mostly melt before adding the next lot.
- Add the cooked pasta, bacon, and half of the onions. Mix through gently.
- Check for seasoning, I added 1.5 teaspoons of black pepper and 1 teaspoon of salt. It will depend which cheeses you used.
- Pour into your baking dish and top with the remaining onions, then sprinkle the panko crumbs in an even layer over the top.
- Bake in the oven for 25 minutes until bubbling and golden.
- Let it sit for 5 minutes before serving.
Rachael deNoyelles says
Such a hit for our Thanksgiving dinner! It was incredible and such a fun take on mac and cheese!
Emilie Pullar says
Yayyy so glad it was a hit Rachael!! Thank you so so much for making, means the world!
Sarah says
This was soooo delicious! Worth the time it takes the onions!! They are so good in it
Emilie Pullar says
Yay so glad to hear!! It's so satisfying seeing them cook down too!
Lucy says
The caramelised onion and panko breadcrumb crunch definitely elevates this dish! ??
Emilie Pullar says
Thanks so much for making it Lucy!!