Heat a non-stick pan. Arrange the chicken drumsticks in a single layer and cook over high heat until the skins are nicely browned. Flip them over for even browning.
Pour in the rice wine and allow to boil until the liquid has almost dried out.
Pour in about half a cup of water, the fish sauce and balsamic vinegar.
Sprinkle the chili flakes and sugar.
Bring to the boil, lower the heat, cover and simmer for about 20 minutes, turning the chicken drumsticks over halfway through the cooking.
Uncover, turn up the heat and continue cooking until the liquid is thick and has reduced to a couple of tablespoonfuls.
Arrange the chicken drumsticks on a platter. Pour the sauce over and around them. Insert a slice of lemon between each drumstick. Slice the basil and sprinkle over the chicken.