Heat vegetable oil in a large skillet over medium-high heat. Add chicken pieces, and cook until lightly browned on all sides, about 5 minutes. Remove chicken from skillet and set aside.
Heat sesame oil in skillet, then add ginger and garlic. Cook and stir until the ginger begins to brown, about 30 seconds. Stir in the reserved chicken, sherry, soy sauce, water, and sugar. Bring to a boil, then reduce heat to medium-low, and simmer until there is only 1/4 cup of liquid left in the skillet, about 20 minutes. Stir in the basil and chiles, and increase heat to medium; continue cooking until the liquid is almost gone.