Silken Chicken is the best way I know to produce delicious tender Chicken for stir-frys. It is important to cut the chicken breast across the grain of the meat, not along the grain. For example: a cooked chicken breast will divide into strings when torn along the grain - so you must cut at right angles to this direction.
2 chicken breast fillets sliced against the grain into thin strips.
1 Tbsp light soy
1 clove of garlic, crushed.
1 egg white, yolk removed
1 Tbsp cornflour (or potato flour)
Mix and marinate all the above ingredients for 1 hour (or longer).
Heat just enough oil to cover the meat until very hot. Groundnut oil is best as it can stand high heat. Carefully drop the marinated chicken into the hot oil, turn off the heat and stir the meat lightly. The oil will have enough residual heat to cook the chicken through in about five minutes. The meat is then strained of oil and transferred to the stir fry for the last few seconds of cooking. This method will ensure lovely tender chicken every time. This method can be adapted for all types of meat fillet - try beef fillet, adding grated fresh ginger to the marinade.