spicy peanut chicken

Ingredients:-
1 tablespoon cornstarch
1 tablespoon sugar
2 tablespoons soy sauce
1 tablespoon white vinegar
1/4 teaspoon ground red pepper (cayenne) (optional)
1 tablespoon vegetable oil
1 pound boneless skinless chicken thighs or breast halves, cut into 3/4-inch pieces
1 garlic clove, finely chopped
1 teaspoon grated gingerroot
2 tbsp serrano pepper 
1/3 cup dry-roasted peanuts
2 medium green onions, sliced (2 tablespoons) (optional)

Method:-

1. Mix cornstarch, sugar, soy sauce, vinegar and red pepper with 2 tbsp of water; set aside.

2. Heat wok or 12-inch skillet over high heat. Add oil; rotate wok to coat side. Add chicken, garlic and ginger; stir-fry about 3 minutes or until chicken is no longer pink in center. Add Serrano peppers; stir-fry 1 minute.

3. Add a teaspoon or two of warm water, cook and stir about 1 minute or until sauce is thickened. 

4. Stir in peanuts. Sprinkle with onions.