6 cups low-sodium chicken or vegetable broth
5 tablespoons unsalted butter, divided
1 onion, cut into 1/4-inch dice
2 1/2 cups 1/4-inch diced sugarpie pumpkin, other cooking pumpkin, or butternut squash (peeled if pumpkin skin is tough or if using butternut squash) (from about 1 pound pumpkin) (see link above for tips on tackling pumpkin)
1 teaspoon coarse kosher salt, or more to taste
1/2 teaspoon freshly ground black pepper, or more to taste
5 teaspoons chopped fresh rosemary, divided
1 1/2 cups Arborio rice
1 cup dry white wine
3/4 cup freshly grated Parmesan cheese
Aged balsamic vinegar for drizzling
In medium saucepan over high heat, bring the broth to boil. Reduce the heat to very low, to keep the broth just below a simmer.
In large saucepan or small stockpot over medium heat, melt 4 tablespoons of the butter. Add the onion and cook, stirring occasionally, until very soft, 8 to 10 minutes (adjust the heat, if necessary, to avoid browning). Add the pumpkin, salt, pepper, and 1 tablespoon of the rosemary and cook, stirring occasionally, until the pumpkin is tender, about 5 minutes. Stir in the rice. Add the wine and cook, stirring, until the wine is absorbed. Ladle in about 1 1/2 cups of broth. Stir constantly until almost all of the broth is absorbed, adjusting the heat to maintain a simmer. Continue adding broth, about 1/2 cup at a time, and stirring almost constantly, adding more broth when almost all of the previous addition is absorbed.
After 15 or 20 minutes, taste the rice for doneness. It should be tender but firm, with no chalkiness in the center, and the overall mixture should be slightly looser than you would ultimately like it (the final addition of cheese will thicken it). If it’s not done, continue cooking, adding broth, and stirring until the rice is done (you may not need all of the broth).
Remove the risotto from the heat and stir in the remaining 1 tablespoon of butter, remaining 2 teaspoons of rosemary, and the cheese. Taste and add more salt or pepper if you like.
Serve the risotto hot, drizzled with the vinegar.