Heat oil in a small heavy-bottomed skillet over medium-high heat. Season chicken breasts with salt and pepper. Brown chicken on both sides, about 3 minutes per side.
Add scallion white parts and ginger. Cook for 1 minute, stirring. Add orange juice concentrate, hoisin or soy sauce, and 1 - 2 Tbsp water. Bring to a simmer and cook until chicken is cooked through, about 3 minutes.
Remove pan from heat, stir in scallion greens and serve.