Pull out head, tentacles, innards, and transparent ribs from body of squid, making sure not to burst the black tint. Cut off tentacles just above the eyes. Discard innards and transparent ribs. Wash and drain squid bodies and tentacles well.
Transfer the cleaned squid into a wok or pan.
Add fish sauce, lemon or calamansi juice, sugar and chili pepper. Let stand for 15-30 minutes.
Cook the marinated squid in high heat while constantly stirring until the liquid almost dried out.