Step 1: Boil the Pasta

Fill a large pot with water and add a generous pinch of salt. Bring it to a rolling boil over high heat. Once boiling, add the 10 oz of medium shells pasta and cook according to package instructions until al dente, which typically takes about 8 to 10 minutes. Stir occasionally to prevent sticking. While the pasta cooks, preheat your oven to 375 degrees Fahrenheit and start preparing the sauce to save time. Al dente pasta holds its shape better in the creamy sauce, ensuring a perfect texture in the final bake.

Drain the pasta well once done, but do not rinse it as the starch helps the sauce cling to the shells. Return the drained pasta to the same pot and set it aside off the heat. This step sets the foundation for combining everything smoothly later. Medium shells work ideally here because their ridges capture the rich cheese sauce.​

Step 2: Sauté Aromatics and Make Roux

In a saucepan over medium heat, melt the 3 Tbsp of unsalted butter. Add the finely minced shallot and cook for just a couple of minutes until it softens and becomes fragrant, stirring frequently to avoid browning. Next, add the 2 minced cloves of garlic and cook for another 30 seconds, just until aromatic. Shallots provide a subtle onion flavor that elevates the sauce without overpowering it.​

Stir in the 3 Tbsp of all-purpose flour and cook, stirring constantly, until the mixture is well combined and bubbly, about 1 to 2 minutes. This creates the roux, the base that thickens the sauce. Keep whisking to cook out the raw flour taste while keeping the heat medium to prevent burning.​

Step 3: Build the Creamy Sauce

Gradually pour in the 2 cups of whole milk and 1/2 cup of heavy cream, whisking vigorously as you add them to avoid lumps. Toss in the 4 leaves of fresh sage. Continue cooking over medium heat, stirring constantly with a whisk or wooden spoon, until the mixture thickens noticeably, about 4 to 5 minutes. The sauce should coat the back of a spoon.

Add a tiny pinch of nutmeg, the 1/2 cup of pumpkin puree, and season generously with salt and pepper to taste. Stir everything together and cook for 1 more minute to let the flavors meld. Remove the saucepan from the heat and discard the sage leaves. The pumpkin adds a subtle warmth and creaminess without dominating, making this perfect for fall.​

Step 4: Combine Pasta and Cheeses

Pour the thickened pumpkin sauce over the drained pasta in the pot. Add 4 oz grated Gruyere, 4 oz white extra sharp cheddar, 4 oz shredded low-moisture mozzarella, and 2 oz Parmesan cheese. Stir really well until all the cheeses melt into the sauce and coat the pasta evenly. The combination of these cheeses creates a luxurious, stretchy texture with nutty and sharp notes.​

Taste the mixture and adjust salt and pepper if needed. Transfer everything to a buttered 2-quart casserole dish, spreading it out evenly. This even layer ensures uniform baking and browning.​

Step 5: Prepare and Add Topping

In a small bowl, combine the 1/2 cup breadcrumbs with 2 Tbsp olive oil. Toss until the breadcrumbs are evenly coated and slightly clumped. Sprinkle this mixture evenly over the top of the pasta in the casserole dish. The olive oil helps the breadcrumbs crisp up beautifully in the oven.​

Step 6: Bake to Perfection

Place the casserole dish in the preheated 375-degree oven. Bake for 20 minutes or until the top is golden brown and the edges are bubbly. Let it rest for a few minutes before serving to allow the sauce to set slightly. Fresh out of the oven, the mac and cheese boasts a crunchy topping contrasting the creamy interior.