Preheat the oven to 400°F. Peal squash and core; cut into 1/4” cubes; toss butternut squash in olive oil, kosher salt, and ground black pepper. Roast squash on a sheet pan for 20-25 minutes until golden brown and tender.
Defrost ground lamb; in a skillet, brown the ground lamb over medium heat. Season with salt and pepper. Remove and set aside.
In the same skillet, melt butter over medium heat. Add sage leaves and cook until butter browns and sage crisps (about 3-4 minutes). Remove sage and set aside.
If you haven’t already, go ahead and mince your shallots; add minced shallots to the brown butter and cook until soft.
Fill a large pasta pot with water; season with kosher salt. Cook Spaghetti until al dente (about 8-10 minutes). Toss with the brown butter, roasted squash, lamb, and shallots. Top with crispy sage and grated cheese.
