Pound garlic and chillies into a coarse paste using a mortar and pestle or a food processor.
Heat the vegetable oil in a large pan/wok. Add the chilli-garlic paste and fry on medium heat constantly stirring for 1-2 minutes.
Add the chicken pieces and then add soy sauce and sesame oil. Cook on high heat till the chicken pieces have cooked. Add sugar, taste and season with salt as desired.
Add the basil and toss well to combine.
Remove from heat and garnish with fresh basil.