Preheat the oven to 200°C (180°C fan). Peel, seed, and cube the squash into 2 cm pieces. Toss with 1 tbsp olive oil, season with salt and pepper, and spread on a baking tray. Roast for 30 minutes until golden edges and tender.

Meanwhile, heat remaining 2 tbsp olive oil in a skillet over medium heat. Add the chopped onion and cook for 5 minutes until translucent, then stir in the garlic and sauté for 1 minute until fragrant.

Transfer the roasted squash, onions, and garlic into a blender. Pour in the vegetable stock and add nutmeg. Blend on high for 1–2 minutes until silky smooth and glossy.

Pour the puree back into the skillet. Bring to a gentle simmer and cook for 10 minutes, stirring occasionally. Season to taste.

Cook 350 g pasta in salted boiling water according to package instructions. Drain, reserving about 60 ml of pasta water.

Toss the pasta with the sauce, adding reserved pasta water as needed to reach the desired consistency.