Start by rinsing the rice thoroughly under cold water until the water runs clear.
Chop the onion, mince the garlic, and slice the mushrooms so everything is ready to go.
Heat olive oil in a large skillet over medium heat. Add the chopped onion and sauté until translucent, about 3–4 minutes.
Stir in the minced garlic and cook for another minute until fragrant. Next, toss in the sliced mushrooms and sauté for 5–6 minutes
Add the rinsed rice to the pot, mixing it gently with the mushroom mixture to toast it slightly for about 1–2 minutes.
Slowly pour the vegetable broth into the pot, ensuring the rice is completely submerged. If using soy sauce, add it now. Stir gently to combine, then bring the mixture to a gentle boil.
Reduce the heat to low, cover the pot with a tight-fitting lid, and let the rice simmer for 15–18 minutes. Avoid lifting the lid during this time to allow the rice to cook evenly.
Once done, turn off the heat and let the pot sit, covered, for 5 minutes to allow the rice to steam and absorb any remaining liquid.