Line 2 baking trays with parchment paper.
Coat the squash in a tablespoon of oil and place on the baking trays. Roast the squash for 25 mins at 220°C/ fan 200°C / gas 7. Remove from the oven and roughly mash two thirds of the squash.
Pour the remaining oil in a large saucepan or dutch oven. Sauté the onions over a low heat for 6-8 minutes, ensuring they do not brown.
Add in the margarine, rice and garlic and fry for 2 minutes. Pour in the wine and bring to a boil, reduce to a simmer and cook until the wine has mostly evaporated.
Add a ladle of warm stock and cook until it has been absorbed. Continue to add a ladle at a time in this manner. Stir continuously over a low simmer for 20-25 minutes.
Meanwhile shallow fry the whole sage leaves in a teaspoon of oil until crispy, this should take a couple of minutes.
When the risotto is al dente, turn off the heat and stir through the chopped sage, zest of 1 lemon, vegan parmesan and the mashed butternut squash.
Finish by sprinkling over the remaining cubes of squash, toasted flaked almonds and vegan parmesan.