Heat oven to 425F.
Arrange butternut squash on baking sheet and dress with just enough EVOO to coat. Season with salt, pepper and nutmeg. Roast 20 minutes, until tender and golden at edges.
Meanwhile, place a large pot of water on to boil for the pasta and start the sauce: In a deep skillet over medium to medium-high heat, heat 2 tablespoons EVOO, 2 turns of the pan. Add pork and render 2-3 minutes. Add chili, onion, garlic, thyme, citrus zest, salt and pepper, and soften 4-5 minutes. Stir in tomato paste, cook 1 minute then add wine, saffron and stock. Reduce 10-12 minutes.
Cook pasta to al dente in salted water, reserving a ladle of pasta water before draining.
Melt butter into sauce, add drained pasta to sauce along with squash and toss to combine. Add starchy water if necessary; sprinkle in some cheese and top each serving with additional cheese and parsley to garnish.