Melt butter in a deep saucepan, over medium heat. Add onion and garlic and cook for 2-3 minutes, unti tender.
Add rice. Cook for 1 minute, stirring constantly.
Add wine and cook until absorbed.
Slowly start to add the chicken broth, 1/2 cup at a time, stirring and cooking until liquid is absorbed.
Once you've added all the broth, start adding water, 1/4 cuo at a time, stirring frequently, cooking until it is absorbed. Add 1- 1 1/2 cups water and test if the rice is cooked. If not, add more water.
Once rice becomes tender and creamy, add pumpkin puree. Stir and cook for 1 minute.
Add 1/2 cup Parmesan cheese and stir.
Serve warm, topped with the remaining cheese and fresh sage.