Heat the slow cooker and add olive oil, then sauté the minced garlic until fragrant, about 1 minute, filling the air with a warm aroma.
Add the Arborio rice to the slow cooker and stir to coat each grain with the garlic-infused oil, watching as the rice becomes slightly translucent around the edges.
Stir in the pumpkin puree, ensuring it evenly coats the rice, creating a vibrant, orange mixture that smells sweet and earthy.
Pour in the warm vegetable broth and add chopped thyme and a pinch of nutmeg. Stir gently to blend all flavors, then cover the slow cooker and set it to low for about 2 hours.
Halfway through cooking, lift the lid briefly to check for doneness; the rice should be tender and the mixture creamy, with occasional stirrings to prevent sticking.
Once the rice is perfectly tender, stir in butter and grated Parmesan cheese, allowing them to melt and enrich the dish, giving it a silky, luscious consistency.
Season with salt and pepper to taste, then give everything a final gentle stir to incorporate the seasoning evenly.
Serve the risotto hot, garnished with an extra sprinkle of Parmesan or a sprig of thyme if desired, and enjoy its rich, creamy texture and seasonal flavor.
