Date Published: Jan 11th, 2025 | Last Updated: Jan 11th, 2025
Author: Abby |Category: mains, sides, vegetarian
Serves: 8 as a main | Prep time: 20 mins | Cook time: 1.5 hours

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French Onion soup + Mac and Cheese. This is it. The ultimate comfort food. There are no short cuts here and no low-calorie nonsense this time. This is the real deal – pile on that butter and pack on the cheese because it’s time to indulge.

This mac and cheese recipe incorporates the essence of a French Onion soup: the sweet caramelized onions, tons of gruyère cheese, and topped with slices of toasted garlic bread. There’s just no better way to marry these two classic comfort dishes. This recipe does take a bit of time to caramelize the onions, but do it slow and low and you won’t regret it!

Anyways, without further ado, here’s the recipe! If you have any comments or suggestions, I’d love to hear from you in the comment section! You can follow me on instagram, youtube and facebook to see all the recipes I post!

Happy cooking!

This recipe is adapted from the NYT version.

Ingredients you’ll need: *This recipe makes a LOT of mac and cheese (8-10 servings), halve the recipe if needed.

• Caramelized onions:
  • 3 Tbsps butter
  • 900g/2 lbs (about 3 large) yellow or sweet onions, sliced
  • 6 sprigs fresh thyme
  • 1 large bay leaf
  • Splashes of beef stock as needed
  • 2 Tbsps sherry vinegar
• Pasta:
  • 1 box (1lb/16oz/454g) of elbow pasta/macaroni
• Baguette toasts:
  • 1 baguette, sliced to 2.5cm thickness
  • 1 garlic clove, peeled
  • 1 cup (4oz) gruyère cheese, freshly grated (do not get the pre-grated cheese)
• Béchamel Cheese Sauce:
  • 2 Tbsps butter
  • 3 Tbsps all-purpose flour
  • 4 cups whole milk
  • 4 cups (170g/6oz) gruyère cheese, freshly grated (do not get the pre-grated cheese)
  • 4 + 1 cups (200g/7 oz) sharp cheddar cheese, freshly grated (do not get the pre-grated cheese)
  • Salt & pepper
• Fresh thyme leaves for garnish

Directions:

Caramelize the onions (you can do this the day before):

In a large deep oven-safe skillet (I use a 5.5 qt braiser enamel cast-iron pot) on MED heat, add in 3 Tbsps of butter, sliced onions, 6 sprigs thyme and 1 bay leaf. Cook until the onions soften (3-4 minutes), then turn the heat down to LOW and slowly continue to cook the onions until they’re a deep brown colour (~45 minutes to 1 hour).

Stir frequently, every 4-5 minutes to ensure the onions don’t burn and scrape the brown bits off bottom regularly. If it seems like it’s about to burn, add a splash of beef stock to loosen everything.

Once the onions are done, add in 2 Tbsps of sherry vinegar to deglaze the pan and scrape up any remaining bits for 30 seconds. Discard the bay leaf and thyme sprig stems. Remove the onions from the pan and set aside.

Make the pasta:

While the onions are caramelizing, cook the pasta according to package instructions with a pinch of salt in the water, but stop cooking 2 minutes before it’s finished. Strain the pasta but reserve the pasta water for later in case needed and run the pasta under cold water until ready to be used.

Make the baguette toasts:

While the pasta cooks, arrange the baguette slices onto a baking tray and broil for 1-2 minutes to lightly toast them until they’re just firm (you don’t need to brown them). Cut the end off of one clove of garlic and rub one side of each toasted baguette slice and set aside.

Make the cheese sauce:

Preheat the oven to 450˚F/230˚C.

In the same pan that was used for the onions, melt 2 Tbsps of butter on MED heat. Once melted, sprinkle in 3 Tbsps of flour. Whisk for 1-2 minutes until the flour is incorporated, bubbles, and turns a light golden brown.

Slowly add in the 4 cups of milk while whisking at the same time to ensure the flour and milk mixes well together without clumps. Let the sauce come to a simmer.

Add back in the caramelized onions (from step 1) and mix together.

Next, add in 4 cups of gruyère and 4 cups of cheddar cheese. Continue to whisk until all the cheese has melted, then add in the cooked pasta (from step 2). Mix it all around, then add salt and pepper to taste.

If you prefer your mac & cheese on the runnier side, add some reserved pasta water (from step 2) to the pot until you reach the desired consistency. Turn off the heat.

Assemble & Bake!

Arrange the garlic-rubbed baguette toasts over the mac and cheese and sprinkle the 1 cup grated cheddar cheese over the top of the toasts.

Bake in the preheated oven for 10-15 minutes until the cheese is bubbly. Broil for 1-2 minutes at the end until the cheese is golden brown.

Garnish with fresh thyme leaves and serve immediately!

Summarized Recipe: