Bring the chicken stock to boil.
Add chicken pieces and corn kernels.
Dissolve corn flour in 1/4 cup water.
Add it to the stock, stirring continuously so no lump is formed.
Let it simmer for 10 mins.
Add spring onion and pepper.
Let it simmer for another 5-7 mins.
Slowly pour in egg white, stirring continuously.
Take off from fire immediately after putting the egg white.
Garnish with coriander leaves / chicken pieces / corn kernels.