Set a 6-qt Instant Pot® to the high saute setting. Melt 2 tablespoons butter; add garlic and onion, and cook, stirring often, until onions have become translucent, about 3-4 minutes.
Add mushrooms and cook, stirring occasionally, until tender, about 3-4 minutes; season with salt and pepper, to taste.
Stir in arborio rice until toasted, about 1-2 minutes.
Stir in chicken broth and thyme. Select manual setting; adjust pressure to high, and set time for 6 minutes. When finished cooking, quick-release pressure according to manufacturer’s directions.
Stir in spinach and remaining 2 tablespoons butter until the spinach has wilted, about 2 minutes. Stir in peas and Parmesan until heated through, about 30 seconds to 1 minute.
Serve immediately.
Notes
Use a variety of mushrooms. This recipe uses cremini mushrooms for convenience and simplicity but feel free to substitute baby bella, chanterelles, shiitake or oyster mushrooms, using an assortment or just one variety.
Do not rinse the rice prior to using. Typically it is recommended to rinse rice under cold water to remove any excess starch. In this case, the excess starch is essential to risotto, providing its creamy consistency. Removing the starch (washing the arborio rice) can lead to gummy risotto.
Deglaze with a splash of wine. Add a splash of dry white wine (pinot grigio or chardonnay) to deglaze the bottom of the pot. This helps prevent the dreaded burn signal while also adding deep flavor by lifting up all the browned bits (fond) and bright acidity to the risotto.
Freshly grated Parmesan goes a long way. Pre-packaged shredded cheese contains anti-caking agents that can hinder their ability to melt smoothly. Freshly grated cheese is always best, melting more smoothly and evenly, and creating a far superior creamy risotto.
Let it rest. The risotto may look soupy initially but allow it to rest for 2-3 minutes before stirring frequently. It will thicken as it sits, transforming into restaurant-quality creaminess.
Make it vegetarian. Vegetable broth can be used for the chicken broth.
Stir in more stock with leftovers. When reheating leftovers, stir in more broth as needed as the rice will continue to soak up the broth.