Chicken Yakitori

Name: Chicken Yakitori
Ingredients: 1½ pounds boned chicken thighs or breasts, skin removed; 10 scallions, ends trimmed and cut into 1-inch lengths; 3 medium green peppers, cored, seeded, and cut into 1-inch squares; 14 6-inch bamboo skewers, softened about 1 hour in cold water to cover; 1 tablespoon canola or corn oil; 1 cup soy sauce; ½ cup sweetened rice wine (mirin); ½ cup sake; 3 tablespoons minced fresh ginger; ¾ teaspoon dried chile flakes