In a wide medium saucepan, sauté 2 tablespoons of butter and the chopped onion over medium heat for 1 to 2 minutes. Then add the sliced mushrooms and cook until the mushrooms have reduced in size, have turned golden brown, and most of the liquid is gone. This should take about 5 to 6 minutes.
Mix through the Arborio rice and sauté until lightly golden brown.
Add white wine. Cook until almost all the liquid is gone from the saucepan.
Over medium to low heat, add 125 ml (½ cup) of chicken stock (or vegetable stock) at a time to the rice mixture. Gently stir the rice through the mixture constantly until almost all of the liquid has absorbed. Repeat until all the stock has been used up.
Remove from heat. Add the grated parmesan cheese and remaining 1 tablespoon of butter to the mixture. Stir through until completely dissolved. Season with salt and pepper to taste.
Allow the rice to sit for 1 to 2 minutes with a lid on. Serve. Garnish with freshly grated parmesan and finely chopped chives or parsley if desired.
Notes
Tips to making risotto:
Use hot broth: When making risotto, it's crucial to use hot broth to keep the rice at the right temperature and ensure that it cooks evenly.
Constantly stir the risotto: This gives the dish its distinctive creamy texture by assisting in the release of the starch from the rice.
Add the broth in ladles at a time, waiting for the rice to soak up each batch before adding the next. This makes it easier to control how the rice cooks and keeps the dish from getting too soggy.
Don't overcook the mushrooms: Overcooking mushrooms can cause them to lose flavor and become tough. Before adding the mushrooms to the risotto, sauté them until they are just barely tender.
Give the risotto some time to rest: After the risotto is finished cooking, give it some time to rest before serving. As a result, the flavors can converge and the risotto gets even creamier.