In a small bowl, whisk together 2 tablespoons of cold water and 1 tablespoon of cornstarch until smooth. Then mix in 3 tablespoons of reduced-sodium soy sauce, 1 tablespoon of rice wine vinegar, 1 tablespoon of sugar (or honey), and 1 teaspoon of grated fresh ginger. Set aside to thicken.
Chop the broccoli, carrots, white button mushrooms, green beans, and onion into bite-sized pieces for even cooking.
In a large skillet, heat 1 tablespoon of extra virgin olive oil and 1 tablespoon of sesame oil over medium-high heat. Add the frozen potstickers and cook for 3-4 minutes until golden. Add 1/4 cup water, cover, and steam for 3-4 minutes. Transfer to a plate.
In the same skillet, sauté onions and mushrooms for 3-4 minutes until tender. Add broccoli and stir-fry for another 3-4 minutes. Finally, add green beans and carrots, cooking for 3-4 minutes until crunchy.
Return potstickers to the skillet with veggies, drizzle sauce over, and toss to coat. Cook for 2-3 minutes until sauce thickens.
Serve garnished with sesame seeds and sliced green onions, alongside rice or quinoa.