Step 1: In a large stock pot, heat broth until simmering. You don't want it to boil but you do want it to stay continuously hot.
Step 2: Heat 4 tablespoons of butter in a large dutch oven or heavy pot over medium heat. Add butternut squash, shallot, and sage leaves. Cook for 8 - 10 minutes or until the squash begins to soften.
Step 3: Once squash begins to soften, stir in garlic. Remove butternut squash from heat and discard sage. Place squash in a small bowl and set aside.
Step 4: Stir the rice into the same pot as that cooked the squash and cook for about 1 to 2 minutes.
Step 5: Add broth to the rice 1 to 2 ladles at a time and stir until each ladleful has been absorbed.
Note: It is very important that you do not rush this process and only add the next ladle of broth only after the previous one has been absorbed by the rice. You may not need to use up all of the stock. Just keep adding broth and stirring until the rice is tender but still relatively firm/asl dente (not mushy). This entire process should take 15 - 20 minutes.
Step 6: At the last moment, a stir in the squash and the parmigiano cheese and season with salt and pepper if desired. Garnish with parsley and serve immediately.