SQUASH: Preheat the oven to 425 ℉ and line a large baking sheet with parchment paper. Toss the cubed butternut squash with 2 tbsp olive oil and 1/4 tsp salt, then spread in an even layer on the prepared baking sheet.
For the roasted garlic: Slice the top off the garlic bulb, exposing the tops of the garlic cloves. Place on a small square of foil or parchment paper and top with the remaining 1 tbsp of olive oil. Scrunch up the foil/paper to seal in the garlic and place the wrapped bulb on the baking sheet with the squash. Roast everything for 35-40 minutes, tossing the squash chunks halfway through the cooking time. The squash should be tender and golden/caramelized in places. After 40 minutes, remove the squash from the oven and place the foil-wrapped garlic directly on the oven rack for an additional 10 minutes.
TOPPING (optional): Toast the pepitas in a dry skillet over medium heat until lightly golden. This should take about 5 minutes – watch them closely as they go from untoasted to burned quickly! Once toasted, transfer to a mortar and pestle and crush the pepitas slightly. You should still have some whole pepitas. Alternatively, use a food processor and pulse briefly.
In the same skillet or saucepan, heat 1 tbsp olive oil over medium heat. Add the chopped sage in as even a layer as possible, and don't stir. It should sizzle immediately and begin to darken and "fry" slightly. Sauté for a few minutes, stirring infrequently, to brown the sage slightly (this allows the flavor to deepen). Be careful not to let it burn.
Transfer the sage to mortar and pestle and crush the leaves to combine them well with the pepitas. Add the salt (1/8 tsp) and toss with a spoon. Set aside your topping until ready to serve.
RISOTTO: When the squash and garlic are about halfway done roasting, start the risotto. Using a 6-quart or larger Instant Pot, turn on the sauté function (to the default "Normal" – not high or low) and add the vegan butter. Once melted, add the rice to the butter and stir to coat. Spread the rice into an even layer on the bottom of the pot and let it sizzle lightly for a minute to toast, then turn off the sauté function by pressing "Cancel". Add the white wine and cook for 1-2 minutes, stirring frequently, or until the liquid is absorbed.
Add the water, coconut milk, and salt. Stir, making sure there is no rice stuck on the bottom or sides of the pot. Put on the Instant Pot lid and set the valve to Sealing, if applicable (some models seal automatically when the lid is turned). Pressure cook on HIGH for 8 minutes. The Instant Pot will take about 10 minutes to pressurize, then will begin counting down. When the timer goes off at the end of the cook time, manually release the pressure. Stir the risotto to combine – it may seem a bit watery, but it will thicken as it cools.
When the risotto is nearly ready, remove the garlic bulb from the foil/paper and squeeze the soft roasted garlic from its papery shells onto the baking sheet. Mash well with a fork, along with 1/3 of the roasted squash. Add this squash/garlic puree to the finished risotto, along with the vegan parmesan and stir well to incorporate.
SERVING: Divide the risotto between serving bowls, top with remaining roasted butternut squash, and garnish with pepitas and sage topping (optional or use more vegan parmesan).
Best when fresh, though leftovers will keep covered in the refrigerator for 2-3 days. Reheat in the microwave or on the stovetop over medium heat, adding vegetable broth or water as needed to rehydrate. Not freezer friendly.