Risotto is one of those dishes with endless possible variations, so once you have a hang of the basic technique, have fun and experiment!
To avoid overcooking your risotto, taste it frequently, beginning about 15 minutes after you add the first ladleful of broth.
In a wide heavy-duty 5- to 6-quart pot, heat the olive oil over medium-low heat. Add the onion and cook, stirring occasionally, until soft and translucent, 5 to 8 minutes.
Meanwhile, in a 3-quart saucepan, bring the broth and 3 cups of water to a bare simmer over medium-low heat.
Add the rice to the onion and stir with a wooden spatula until the grains are coated with oil, slightly translucent around the edges, and opaque in the center, 2 to 3 minutes.
Add the wine, raise the heat to medium, and stir until almost evaporated, about 1 minute.
Using a large ladle, add about 3/4 cup of the broth. Stir, mixing any rice sticking to the pot’s sides back into the mixture, until most of the broth is absorbed, the rice no longer seems loose when you shake the pot, and a wide trail forms when you run the spatula across the bottom of the pot.
Continue to add broth in 3/4-cup increments, stirring constantly and scraping around the edge of the pot, until the rice is al dente (still a bit firm to the bite but without a hard or crunchy center) and most of the broth is absorbed, 18 to 22 minutes. (You may or may not use all of the broth; if you run out, use hot water.)
Immediately turn off the heat. Add another 3/4 cup broth and the butter, Parmigiano-Reggiano, and salt and pepper to taste, and stir quickly. Cover with a tight-fitting lid and let sit for 5 minutes. Stir again and serve.
Butternut Squash, Pancetta, and Sage Add 4 oz. chopped pancetta with the onions and cook as directed. Add 3 cups 1/2-inch-diced butternut squash and cook, stirring, for 5 minutes. Continue with the basic risotto. Add 1 Tbs. chopped fresh sage along with the butter and Parmigiano-Reggiano.
Porcini Mushroom and Gorgonzola Gently simmer 1/2 oz. dried porcini mushrooms in 1/2 cup heavy cream until softened, about 5 minutes. Remove the mushrooms from the cream, coarsely chop, and return to the cream. Cover and keep warm while you make the basic risotto. At the end, instead of broth and butter, add the mushroom cream, 4 oz. room-temperature gorgonzola, and just 1/2 oz. finely grated Parmigiano-Reggiano.
Shrimp, Cherry Tomatoes, and Saffron On a foil-lined rimmed baking sheet, roast 3 cups cherry tomatoes tossed with 1 Tbs. olive oil at 450°F until soft and brown in spots, 15 to 20 minutes. In a large skillet, cook 1 lb. shelled and deveined large (31 to 35 per lb.) shrimp in 1 Tbs. olive oil over medium-high heat until just opaque, about 2 minutes. Instead of chicken broth, make the basic risotto with fish stock or bottled clam juice heated with a large pinch of saffron. Add the shrimp and tomatoes along with the butter and Parmigiano-Reggiano.
Roasted Fennel and Lemon Remove the fronds from 1 lb. fennel, chop, and set aside. Trim and cut the fennel bulb into 1/2-inch pieces. On a large heavy-duty baking sheet, toss with 2 Tbs. olive oil and roast at 375°F, stirring once, until tender and golden, about 30 minutes. Make the basic risotto. Add the roasted fennel, fennel fronds, 1 tsp. finely grated lemon zest, and 1 Tbs. lemon juice along with the butter and Parmigiano-Reggiano.
2 Tbs. olive oil
1 medium yellow onion, finely chopped
3 cups lower-salt chicken broth
14-1/2 oz. (2 cups) arborio, vialone nano, or carnaroli rice
1/2 cup dry white wine, such as Sauvignon Blanc or Pinot Grigio
1 oz. (2 Tbs.) unsalted butter, cut into 4 pieces
2 oz. finely grated Parmigiano-Reggiano (2 cups using a rasp grater)
Kosher salt and freshly ground black pepper