Step 1: Heat the vegetable broth in a medium saucepan over low heat and keep it at a bare simmer throughout the process.
Step 2: In a large skillet or Dutch oven, heat the olive oil over medium heat and fry half of the sage leaves until crispy; remove and set aside for garnish.
Step 3: Add 1 tablespoon of butter to the same pan and sauté the shallots and garlic until soft and fragrant, about 3 minutes.
Step 4: Add the Arborio rice to the pan and toast for 2 minutes, stirring constantly until the grains are translucent at the edges.
Step 5: Pour in the white wine and stir until the liquid is fully absorbed by the rice.
Step 6: Add the warm broth one ladle at a time, stirring frequently. Wait until each ladle is absorbed before adding the next one.
Step 7: When the rice is halfway cooked (about 10 minutes in), stir in the pumpkin puree, chopped remaining sage, and nutmeg.
Step 8: Continue adding broth and stirring until the rice is tender but firm to the bite (al dente).
Step 9: Remove from heat and stir in the remaining butter and Parmesan cheese. Season with salt and pepper.
Step 10: Cover and let rest for 2 minutes before serving topped with the crispy sage leaves.