Step 1

In a small bowl, whisk the soy sauce, water, dry sherry, sesame oil, sugar, cornstarch, red pepper flakes and dry mustard together. Set aside.

Step 2

In a large nonstick skillet, bring 1 inch of water to a rapid boil. Add the broccoli and cook for 2-3 minutes, or until tender-crisp. Strain the broccoli in a colander and then run under cold water to stop the cooking process. Set aside and allow to fully drain.

Step 3

Wipe the skillet dry. Add 2 tablespoons of vegetable oil and heat over high heat. Add the shiitake mushrooms and red peppers and cook, stirring occasionally, for 5-6 minutes, until the mushrooms are browned and the peppers are softened. Add the garlic, white/light green scallions, and ginger; cook, stirring constantly, until fragrant, about 30 seconds. Return the broccoli to the pan and cook until warmed through, about 1 minute. Add the reserved sauce. Toss and cook until the sauce is thickened and the vegetables are evenly coated, about 30 seconds. Transfer to serving dish and sprinkle with dark green scallions. Serve with rice, if desired.