Preheat the oven to 400 degrees Farenheit.
Cut the butternut squash in half and place face down on a baking pan lined with parchment paper.
Cut the tomatoes into quarters and add to the baking tray.
Bake for 30-40 minutes or until the squash can be easily pierced with a fork.
While that is cooking, add the chopped onion and minced garlic to a large pot with the olive oil.
Saute until translucent.
Add in the whole sage, salt and pepper.
Add the rice and let brown for about 2 minutes.
Add the wine and cook until all liquid has evaporated.
Add 1/2 cup of vegetable broth and cook until the liquid is absorbed/evaporated. Continue with this process until the rice is cooked through. Be sure to only add in 1/2 cup broth at a time, and stir occasionally until it is absorbed before adding in the next 1/2 cup.
When the squash and tomatoes are done, let cool or use an oven mitt to peel off the skins of the tomatoes and remove the seeds of the squash. Add the peeled tomatoes to a blender.
Measure out 2 cups worth of the squash flesh and add to the blender. Process until smooth.
Add to the risotto and mix well.
Remove the sage leaves, stir in the cashew parmesan and black pepper. Taste and adjust flavors as desired. Serve warm.