Heat olive oil in a large skillet or wok over medium-high heat.
Add bell peppers, broccoli, snap peas, carrots, and mushrooms. Stir-fry for 5–7 minutes until crisp-tender.
Stir in garlic and ginger, cooking for another 30 seconds.
In a bowl, whisk soy sauce, maple syrup, rice vinegar, and sesame oil.
Pour sauce over the veggies, then stir in the cornstarch mixture to thicken.
Simmer for 2 minutes until the sauce coats everything.
Serve over rice or noodles, then sprinkle with sesame seeds and green onions.
Enjoy immediately!