Bring 4 quarts water to boil in a large pot.

Add salt and rice to boiling water and cook, uncovered, until tender, 10 to 15 minutes.

Drain rice and spread on rimmed baking sheet to cool completely.

Heat vegetable oil in a large skillet over medium heat until shimmering.

Cook mushrooms, covered, until softened, about 2 minutes.

Remove lid.

Add peas and cook until they are bright green, about 2 minutes.

Add ginger and garlic and cook about 30 seconds.

Off heat, stir in vinegar, sesame oil, and honey.

Pour mushroom mixture over cooled rice and mix until combined.

Season with salt and pepper if desired.