Heat the oil in a wok or large frying pan. Add the shallots, chilli and garlic and cook for 1 minute. Remove with a slotted spoon and keep warm.
Add the chicken to the pan, stir-fry for 5 minutes until cooked and beginning to brown. Return the shallot mixture to the pan, then add the fish sauce, soy sauce and basil and cook for 1 minute until the basil starts to wilt. Sprinkle with toasted coconut flakes, if using, and serve.