Heat the oil in a large wok on medium-high. Add garlic cloves and ginger until garlic cloves are lightly browned.
Add quails, stir fry for 5 minutes, add soy sauces, chili bean sauce and sugar. Stir well until quails are evenly coated.
Pour the beer into the wok, cover, and simmer until the sauce reduce to a stick coating. Add green pepper and onion, stir fry for 1 minute, add salt as needed.