Marinate the chicken in the soya sauce, cornflour and sugar.
Cut the mushroom into thin peices.
Heat half the oil in the saucepan. Add in the chicken and stir fry for 3-4 minutes, till it looks cooked. Remove the chicken into a dish.
Heat the remaining oil. Saute the garlic in the oil till a lovely aroma spreads in your kitchen (WOW!!!).
Now put in the mushrooms along with the salt and pepper and saute on high heat for 3 minutes.
Add the chicken back and saute for a couple of minutes till the flavors are mixed in well. Serve warm.