Add the vegetable broth and pumpkin puree to a medium saucepan. Whisk until combined and bring the mixture to a gentle simmer over medium heat. Reduce the heat to low and keep covered.
Melt the butter in a large saucepan over medium heat. Add the minced shallot and cook until softened, about 3–4 minutes.
Stir in the thyme and Arborio rice. Cook for about 1 minute, stirring constantly, until the rice is lightly coated with butter.
Add the white wine and stir to deglaze the pan. Cook until most of the liquid has evaporated.
Add one ladleful of the warm pumpkin broth to the rice. Stir occasionally and cook until most of the liquid has been absorbed.
Continue adding the warm broth one ladle at a time, allowing each addition to absorb before adding more. Stir regularly to help the rice release its starch.
Continue cooking for about 20–25 minutes, or until the rice is creamy and tender but still has a slight bite.
Remove from the heat and stir in the Parmigiano Reggiano, parsley, lemon juice, and half of the goat cheese. Season with salt and black pepper to taste.
Spoon the creamy Pumpkin Goat Cheese Risotto into serving bowls and top with the remaining goat cheese and pomegranate arils.
Serve immediately while warm and creamy.