Carefully slice the butternut squash in half lengthways. Scoop out the seeds and reserve for later.
Score through the flesh of the squash, without going through the skin, in a diamond pattern. Place onto a baking tray and drizzle over half of the olive oil. Season and roast in the oven for 30-35 minutes, or until soft through when pierced with a knife. Scoop out the flesh, keeping for later, leaving about a 1 cm border of flesh around the edges.
Set a large saucepan with the remaining olive oil over a medium heat. Brown the beef mince for 6 minutes, until beginning to turn crisp. Stir through the cinnamon, tomato puree, sieved tomatoes and pumpkin seeds. Simmer gently for 10 minutes, until the liquid has evaporated. Season and remove from the heat. Stir through the reserved butternut squash.
Divide the meat mixture between the hollowed-out squash. Scatter with the sage before serving.