Soak rice in 3 cups of vegetable broth for 10-15 minutes.
Heat 2 tablespoons of olive oil in a large pan over medium heat. Add mushrooms and cook, stirring regularly for 8-10 minutes until browned.
Add onions, and garlic and cook for 2 minutes, stirring frequently. Add the soaked rice in the vegetable broth and season with thyme, salt and pepper. Stir to loosen any rice and deglaze the pan.
Reduce heat to medium-low and cook for 15 minutes until the liquid is absorbed, stirring occasionally.
Turn the heat to low. Stir in the remaining 1 cup of broth, grated parmesan cheese, and peas. Cook for an additional 2-3 minutes, stirring regularly.
Serve right away with fresh thyme and more grated cheese.
Video
Notes
Storage: Store leftovers in an airtight container for up to 5 days.