Warm the vegetable broth in a saucepan over low heat and keep it warm the whole time you cook.
Heat the olive oil in a large wide pan over medium high heat. Sear the mushrooms for 6-7 minutes until deeply golden, season lightly, then transfer to a plate.
In the same pan, melt 2 tablespoons of the dairy free butter over medium heat and cook the onion for 4 minutes until soft. Add the garlic and cook 1 minute.
Stir in the arborio rice and toast for 2 minutes until the edges of the grains turn translucent.
Pour in the white wine and stir until fully absorbed.
Add the warm broth one ladle at a time, stirring often and waiting until each addition is mostly absorbed before adding the next. Continue for 18-20 minutes until the rice is creamy and just tender.
Stir in the seared mushrooms, the remaining dairy free butter, nutritional yeast, thyme, salt and black pepper. The nutritional yeast gives it that savory parmesan style finish.
Rest for 2 minutes, then top with fresh parsley and serve immediately while the risotto is loose and creamy.