Place 2.5 cups of butternut squash in a large bowl and drizzle with 1 tablespoon of olive oil and season with 1 teaspoon of salt, brown sugar, ½ teaspoon of black pepper, and cayenne pepper. Massage the oil and seasonings into the butternut squash with your hands. Let the butternut squash sit for 15 minutes.
Add the remaining salt and pepper to a small bowl, you will use this mixture to season the risotto in layers.
Add ½ tablespoon of oil to a large stock pot. When the olive oil is fragrant add half of the white onion to the pot and season with salt and pepper from the salt and pepper bowl. Sauté the onion for 2 minutes and then add 3 cloves of minced garlic to the pot and sauté for another minute.
Add the broth, coriander, nutmeg, and sage leaves to the pot and bring to a boil over high heat. Turn the heat to low and simmer until the risotto is ready to be prepared.
Next, heat a large skillet with sides over medium/high heat and add 1 tablespoon of olive oil to the skillet. Add the cubed butternut squash that has been sitting for 15 minutes to the pan and toss with olive oil. Cover the skillet and let the butternut squash cook for 3-4 minutes. Uncover the squash and toss and add the rest of the onion and garlic to the skillet. Cover and let the squash cook for another 3-4 minutes. The goal is to let the squash caramelize and soften.
Deglaze the pan with the white wine and allow the squash to cook in the wine for 2-3 minutes.
Once the squash is soft, use the back of a fork to mash the squash into a puree. Move the squash puree to one side of the skillet and add the butter to the opposite side of the skillet. When the butter is melted add the remaining squash and arborio rice to the pan and toss.
Turn heat to medium and add ¾ cup of the broth mixture to the skillet and stir until the broth absorbs completely. Season with a pinch of salt and pepper. Repeat this step until there is about ½ cup of broth left. This takes about 30 minutes. Do not rush this! After you’ve used about 7.5 cups of broth, your rice should be almost cooked. Give it a try to see if it’s close to al dente. If it’s still very hard, you’ll need to add the remaining broth.
Add the final ½ cup of broth to the rice and let it absorb about halfway and then add grated parmesan cheese. Stir until the cheese is melted.
Remove from heat and season with cracked black pepper and fresh sage.