Heat the oil in a frying pan or wok, add the onion and pepper chunks, then the peas and grated ginger.
Fry for 2-3 minutes, then add the chicken pieces. Cook for about a minute until the chicken warmed through, then pour over the eggs and sprinkle with the chopped coriander.
Stir and let the eggs evenly spread around by tilting the pan. Cook, under cover, for about 5 minutes.
Scatter the bean sprouts on top, then fold the omelette in half. Fry for another minute or so.
Slide onto a plate, cut in half and serve with Hoisin sauce.