Prep sauce: In a small bowl, whisk together soy sauce, rice vinegar, maple syrup, and cornstarch slurry.
Cook veggies: Heat sesame oil in a large pan or wok over medium-high heat. Add garlic and ginger, sauté 30 seconds. Add broccoli and cook for 3–4 minutes until bright green. Add mushrooms and cook another 3–4 minutes, until tender.
Add sauce: Pour in the sauce and stir to coat. Let simmer for 2–3 minutes until thickened.
Serve: Over rice, quinoa, or noodles. Top with green onions and sesame seeds if desired.
