1. Finely slice the lemongrass (or lemon zest). Peel and chop the ginger and garlic. Heat the oil in a pan, over high heat. Add the lemongrass or lemon zest, ginger and garlic, and sauté for 30 seconds, until fragrant.
2. Add the chicken and stir-fry for 2 minutes. Then, add all the vegetables and stir-fry for 5 minutes, until the chicken is cooked through and the vegetables are almost cooked.

3. Finally, add the peanuts, oyster sauce, sugar, and seasonings to taste. Stir-fry for 1 minute, to combine flavors. Serve immediately, garnished with cilantro leaves and steamed rice.