Step 1

Make the sauce: Whisk all the ingredients together in a small bowl, making sure the cornstarch is dissolved; set aside.

Step 2

Make the stir-fry: Heat a flat-bottomed wok or large frying pan over medium-high heat until a drop of water vaporizes immediately on contact. Drizzle 1 tablespoon of the oil around the pan, add the broccoli, and season with salt. Using a metal spatula, stir-fry until it begins to soften and brown around the edges, 1 to 2 minutes. Transfer to a large plate.

Step 3

Drizzle 1/2 tablespoon of the oil in the pan, add the mushrooms, and season with salt. Stir-fry until browned and softened, 1 to 2 minutes. Transfer to the plate with the broccoli.

Step 4

Drizzle the remaining 1 1/2 tablespoons oil in the pan, add the peppers, snow peas, garlic, and ginger, and season with salt. Stir-fry until the garlic and ginger are fragrant and the vegetables are softened, about 1 minute.

Step 5

Add the reserved broccoli and mushrooms and any accumulated juices back to the pan and stir to combine. Stir the sauce one more time, pour into the pan, and cook, stirring constantly, until the sauce is thickened and coats the vegetables, 1 to 2 minutes. Serve over rice or noodles and top with the peanuts.