Peel the carrots and slice them thinly. Clean the French beans and snap peas. Chop the white part of the lemongrass thinly. Remove any hard part.
Take a large wok and heat it. Add the oil, then after 30s, add the garlic, ginger and lemongrass. Cook for a few mns and add the chicken (You might need to do a few batches depending on how big your wok is). Cook for about 5 mns.
Add the carrots and French beans and cook for 5 mns. Add the snap peas and cook for a few more mns before adding the freshly chopped coriander. Add the fish sauce with the shrimps, and let cook for a few more mns.
Season with pepper as needed.The vegetables should not be overcooked but remain firm.
When the shrimps are cook, stop the heat and cover for a mn before serving.