In a saucepan, heat the vegetable broth over low heat and keep it warm.

In a large saucepan, heat olive oil over medium heat. Add the chopped onion and garlic, sauté until translucent.

Add the sliced mushrooms and cook until they are browned and tender.

Stir in the arborio rice and cook for 1-2 minutes until the rice is lightly toasted.

Begin adding the warm vegetable broth, one ladle at a time, stirring frequently. Wait until the liquid is mostly absorbed before adding more broth.

Continue this process for about 18-20 minutes, or until the rice is creamy and al dente.

Stir in the nutritional yeast, salt, pepper, and thyme. Mix well and adjust seasoning to taste.

Remove from heat and let it sit for a couple of minutes before serving.