Pre-heat the oven to 375 and line a sheet tray with a silicone mat or aluminum foil. Lay out the chicken, broccoli, scallions, red pepper and cashews on the tray in a single layer. Then whisk the soy sauce, vinegar, sesame oil, garlic and ginger together in a bowl and pour it over the chicken and veggies. Use a spoon to quickly toss it all together thoroughly, then roast everything for 25-30 minutes. Serve immediately over some rice or quinoa with a sprinkle of sesame seeds on top! Enjoy!!