Heat the oil on a wok (or skillet) over medium-high heat.
Once the oil is ready, add the garlic.
Cook until the garlic turns slightly brown.
Add the pieces of chicken.
Cook until the chicken is no longer pink --- and almost cooked.
Add the sugar, soy sauce, oyster sauce, and pepper.
Add the mushrooms.
Mix to combine everything and continue cooking until the chicken is completely cooked.
Add the ginger, chili, and spring onions.
Mix to combine, then remove the wok from the heat.
Transfer into plates, then serve --- garnish with more spring-onions, if desired.