Chop ends off butternut squash, then slice into quarters and scoop out the seeds. Add to a parchment paper-lined baking sheet, along with halved onion and rub them with olive oil. Chop the top off a head of garlic, then add to tray and drizzle with remaining olive oil. Roast in a preheared 400℉ oven for 30-40 minutes or until fork-tender.
Boil pasta according to package instructions. When noodles are al dente, drain, reserving 2 cups of pasta water for the sauce.
Allow 4 tablespoon of butter to brown slightly over medium-low heat, stirring often. Reduce heat to low and add 7 sage leaves, frying for about 30-60 seconds. Remove sage and drizzle infused butter over pasta, then gently stir to coat noodles.
Chop squash into cubes, then add to a large bowl (or blender) along with roasted garlic cloves (peeled), onion, pasta water, fresh thyme, 3 fresh sage leaves, smoked paprika, cayenne pepper, nutmeg, salt, mustard, and milk. Blend until smooth.
Reduce heat to low and add sauce to pasta, gently stirring until incorporated. Shred the cheddar, Gouda, and half of the Parmesan, then mix until combined.
Serve in individual bowls and top with remaining Parmesan cheese, pepitas, red pepper flakes, and a small swirl of truffle oil (optional).
Notes
The sage leaves should be nice and crispy after frying in butter. I recommend setting them aside and using them as a garnish later!
Want to make it high protein or gluten-free? Use chickpea pasta instead of rigatoni!
After roasting, let your veggies cool slightly before cutting & blending so the steam can escape.
Instead of tossing the seeds, you can use them to make these spicy roasted pumpkin seeds.
I recommend shredding blocks of cheese rather than buying the cheese pre-shredded, as this usually results in a creamier, less stringy texture.
Finish it off with a high-quality truffle oil. Cheap truffle oils tend to have an artificial taste that can ruin an entire dish!