Preheat the oven to 350ºF. Cut the butternut squash in half (from the top of the stem and down). Remove the seeds from the middle and lightly brush a little bit of oil on the inside of both halves. Place the butternut squash halves face down on a lined baking sheet. Bake for 30-40 minutes or until a knife can go through it with ease. Set it aside and let it cool.
Once your butternut squash is cooked, heat a large cast iron pan (or pan of choice) over medium heat. Add 2 tsp of oil to it. Once heated, add the chopped onion and garlic to it.
After a few minutes, add the rice to the pan. Stir the rice around the pan for roughly 1 minute. Then add the white wine. Let this combo simmer together. Once the white wine has mostly been absorbed add 1 cup of the vegetable broth to the rice. Stir, and let this simmer on medium heat. Once that cup of vegetable broth has been absorbed, add another cup of the vegetable broth and stir and simmer. Continue to do the same for the next 2 cups of vegetable broth.
Before adding the last cup of vegetable broth. Remove the butternut squash from its skin and process in a food processor until it's smooth and a puree has formed. Measure out 1/2 cup and set aside. USe the rest of the butternut squash in another recipe (perhaps in a cozy soup!)
Add the miso paste, thyme, salt and pepper to the rice mixture and then add the last cup of vegetable broth. In the end you want the consistency of the risotto to be thick, and creamy. But don't let all the broth get absorb this last round through. When it is a little more runny then you would like, add the nutritional yeast, and the butternut squash puree into the rice. Stir to incorporate an then let it simmer for a little longer.