Place the chicken thighs in a bowl and add the cornstarch, salt, and pepper. Toss the chicken in the cornstarch until fully coated.
Heat the oil in a large frying pan (skillet) over a high heat.
Add the chicken thighs, and cook on one side until golden brown (about 4-5 minutes), then turn over and cook for a further 2 minutes.
Add the butter to the pan, let it melt, then add the garlic and stir together. Turn the heat down to medium so the garlic doesn't burn, then make the sauce.
To make the sauce, combine the honey, stock, rice vinegar, and light soy sauce in a bowl and stir together.
Add the sauce to the pan. Turn the heat up and bring the sauce to the boil, then simmer for 4-5 minutes until the sauce reduces and thickens, and the chicken is cooked through (and no longer pink in the middle).
Sprinkle on the chopped parsley and chilli flakes and serve over boiled rice.
