1 butternut squash ‘trunk’, trimmed, peeled and cut into 1–2cm/½–¾in chunks
3 garlic cloves, thinly sliced
1 heaped tbsp finely chopped fresh sage, plus 2 extra sprigs for the topping
350g/12oz dried spaghetti, snapped into thirds
freshly ground black pepper
2 vegetable stock cubes, crumbled
80g/2¾oz hard vegetarian cheese, finely grated, plus extra to serve if preferred