Butternut Squash & Rosemary Mac N' Cheese

My brother-in-law, Jeremiah, is going to a potluck for his fraternity. It's their Thanksgiving dinner, so he asked if I could create a dish for him to bring. (The text that he sent me literally said: "something to bring to XPO Thanksgiving...whatever can feed a bunch of hungry dudes") Oh, and there's one more catch: a $10 budget for extra ingredients. I always love getting these kinds of requests, so I happily accepted.

Planning mode commenced and, for some reason, I immediately set my heart on macaroni and cheese. A) It's something that is substantial and feeds a crowd. B) The basic ingredients are inexpensive, but the recipe can be easily "dressed up" for the holidays. And, C) Macaroni and cheese, obviously, screams "comfort food". Thanksgiving is one of the most "get comfortable and just eat all day" holidays of the year. So, I started to brainstorm on how I could incorporate classic Fall flavors...Pumpkin?...Sweet potato?...How about...butternut squash! Brown Eyed Baker has a recipe for Butternut Squash & Bacon Mac n' Cheese that I absolutely adore. A tasty mash of butternut squash is blended into the creamy cheese sauce. With that as my inspiration, I made my own twist for the 2012 XPO Thanksgiving: Butternut Squash & Rosemary Mac N' Cheese!

First, I started with the mash. Butternut squash and rosemary were 2 of the 4 ingredients that I had to buy, but were only $4 out of my budget. Yummy? Inexpensive? Awesome. I was highly motivated by the enormous display of squash at the grocery store, too. Big pumpkins, little pumpkins, acorn squash, butternut squash...Green, yellow, orange...

Ultimately, I chose a small, 1.5 lb butternut squash. Its rich, sweet, and nutty flesh would be a pleasant surprise in this baked mac n' cheese. I halved the squash and scooped out the seeds.

I always notice the scent of the squash immediately, reminding me of pumpkin carving and just making me think of other Autumn-y things.  Ah, happy sigh.

I only used 2 heaping cups of diced squash for this recipe, saving the other half for another day. (To make some chili, perhaps?)

Brown Eyed Baker's original recipe calls for bacon, but I didn't have any on hand (blasphemy?!) and couldn't really fit it into my tiny $10 budget. For a split second, I thought about cheating and just buying some anyway. I was probably staring at the bacon section for a good 5 minutes (...totally normal...) Alas, my conscience kicked in. Cheating is no fun. And the XPO potluck rules say, $10 limit! So...I opted for some fresh rosemary instead! I love rosemary. It's a fragrant, woodsy herb that goes amazingly well with hearty squash. (It also reminds me of the big, juicy turkey roasting in the oven on Thanksgiving!)

If I can't have bacon fat, butter is the next best thing. So, in a little bit of melted butter, I caramelized diced yellow onion. Once the onions were browned and smelling sweet, I added the diced butternut squash. This vegetable mixture cooks and continues to caramelize for 2-3 minutes, then it's seasoned with salt, pepper, and finely chopped rosemary. (Your kitchen will smell extraordinary.)

Once the squash was tender, I transferred the vegetables to a small bowl. I mashed everything with a fork, then set it aside while I cooked the pasta and made the cheese sauce.

The 3rd, extra ingredient I had to buy was the pasta. My favorite pasta to use for macaroni and cheese is the spiral-shaped cavatappi, just like Michelle from Brown Eyed Baker prefers. The ridges on these little corkscrew pasta are perfect for holding on to the rich, gooey cheese sauce. If you can't find "cavatappi", Barilla's "cellentani" and "elbows" (pictured) are actually the same thing. I cooked them for 6 minutes only, just short of being "al dente".

While the pasta was boiling, I made the bechamel. (I've made bechamel, or "white" sauce, on the blog before, but for Cheesesteak Paninis.) To do this, simply melt 4 tbsp of unsalted butter, whisk in equal parts all purpose flour, and cook this roux for 1 minute. You can smell the difference in the roux while it cooks, going from "raw, pasty flour" to "nutty and toasty". Next, slowly pour in 3 cups of milk. Whisk continuously to avoid lumps and burning on the bottom. After 5 minutes, the sauce will start to thicken.

My 4th and final extra ingredient? Cheese. Cheddar and mozzarella cheese! At this point, I added the shredded cheese 1 cup at a time. I used a wooden spoon to stir and completely combine before adding the next cup. This helps to make a smooth, creamy sauce.

See? Absolutely smooth and creamy. I also added an extra cup of milk because the sauce was a little too thick for my liking. If you'd like to add even more richness, feel free to use a cup of half-and-half or heavy cream.

Finally, the mashed butternut squash and semi-cooked pasta go in!


(Sorry. That's all I've got.)

After pouring the mac n' cheese into a buttered casserole dish, I sprinkled the melted butter & breadcrumb mixture over the top. I used panko instead of plain or Italian-style because I like the big crunch you get from a thick layer of panko breadcrumbs.

Since Jeremiah wasn't going to dinner for another few hours after I originally cooked this, I covered and refrigerated the mac n' cheese. Then, when he came to pick it up, I baked it at 400 degrees for about 20 minutes. I also put it under the broiler for an extra minute at the end, so that the breadcrumbs could get really brown and crispy.

However...I can't just make something for a party and not taste-test it...So I made a mini-casserole dish of mac n' cheese for myself on the side. ;)

The pasta becomes perfectly cooked while baking. Each little corkscrew fills up with cheesy sauce and is the perfect gooey bite. Then, there are tender bits of rosemary-infused butternut squash and sweet, caramelized onions all throughout. The layer of buttery panko breadcrumbs gives the dish even more texture. Crispy and crunchy deliciousness. Make this mac n' cheese for a new, interesting addition to your Thanksgiving spread...or just enjoy it for dinner on any Autumn day! :)

Butternut Squash & Rosemary Mac N' Cheese (adapted from Brown Eyed Baker: Butternut Squash & Bacon Mac n' Cheese; serves 8)

Print Recipe
10 tbsp Unsalted Butter, divided
2 cups Diced Butternut Squash
1/4 of a Yellow Onion, diced
1/2 tsp Fine Sea Salt
1/4 tsp Black Pepper
1 tbsp Finely Chopped Fresh Rosemary Leaves
4 tbsp All Purpose Flour
4 cups Whole Milk, divided
1 1/2 cups Shredded Mozzarella Cheese
1 1/2 cups Mild Cheddar Cheese
1 lb Cavatappi Pasta
1 cup Panko Breadcrumbs

  1. Preheat oven to 400 degrees. Grease a 2 1/2 qt casserole dish or a 13x9 dish. Bring a pot of salted water to a boil for the pasta.
  2. In a skillet over medium heat, melt 1 tbsp of butter. Add the diced onions and saute for a few minutes, until the onions begin to caramelize. Add 1 more tbsp of butter, add the butternut squash, and also saute until slightly caramelized, about 2-3 minutes. Then, season the vegetable mixture with salt, pepper, and rosemary. Stir to completely combine and cook the squash for an additional 8-10 minutes. Once the squash is tender, transfer the mixture to a small bowl and mash the vegetables until as smooth as you prefer. Set aside until ready to use.
  3. Boil the pasta until 1 minute short of being "al dente" (1 minute less than the instructions state on the package). DO NOT fully cook. When the pasta is "almost-al dente", strain and set aside until ready to use.
  4. Make the cheese sauce while the pasta is boiling. In a large saucepan over medium heat, melt 4 tbsp of unsalted butter. Add the all purpose flour, whisk until smooth, and cook this roux for 1 minute. Slowly pour in 3 cups of the milk, whisking continuously to avoid lumps. Whisk the mixture once every minute, to avoid lumps and burning on the bottom. 5-6 minutes later, the sauce will begin to thicken. At this point, add 1 cup of cheese, stir with a wooden spoon to combine, then repeat this process with another cup of cheese until all of the cheese is melted in. Pour in the last cup of milk. Season with salt and pepper to taste, then turn off the heat.
  5. Add the drained pasta and mashed butternut squash to the cheese sauce. Stir with a wooden spoon until everything is completely combined and evenly distributed. Pour the mixture into the prepared casserole dish. 
  6. In a small bowl, microwave and melt the remaining 4 tbsp of butter. Then, add the 1 cup of breadcrumbs. Stir to combine. Sprinkle this mixture, in an even layer, over the top of the mac-n-cheese.
  7. Bake the mac-n-cheese until browned and bubbly, about 10-12 minutes. Allow the casserole dish to sit at least 10 minutes before serving.
  8. Serve as a side or a meatless entree! Enjoy!