Slice open squash, seed and then cut into strips, seasoning with salt and olive oil. Place on a shallow baking sheet.
Roast skin side down in a preheated oven at 450°F until tender and golden, about 50 minutes. Cut flesh from the skin and cube into 1/2 inch pieces. This can be done ahead of time. Otherwise you can start the risotto when the squash has about 10 minutes left to cook.
Simmer the broth in a medium sized pot.
In a large heavy pot, add onion in 2 tbsp. of EVOO, stirring until softened, about 6minutes on medium heat. Add the rice, garlic, and cumin, stirring for 3 to 4minutes. This coats the rice and prepares it for its transformation into creamy goodness.
We are now going to begin adding the liquid. Add the wine and stir until it has been absorbed, and then begin adding the hot broth, 1/2 cup broth at a time stirring frequently, until broth is absorbed. Keep repeating until rice is creamy-looking but still al dente, about 18minutes total.
Stir in the squash, then stir in cheese, sage, spinach, stirring to combine.
Serve risotto immediately, grating fresh parmesan on top.
I always make more than I need so I can make risotto cakes the next day, shaping into patties, dipping in egg and crumbs and then pan frying. Serve plain or with your favorite sauce.