The Japanese dip hard-boiled quail eggs in fish, shrimp and vegetables sauce and fry in high fat.
The British version is Scottish eggs, where hard-boiled eggs are rolled in a mixture of meat and flour and then fried in high fat.
Chinese street vendors sell quail eggs that are hard-boiled inside. Must be very tasty, but because the tea color is egg white to dirty brown, it may cause malfunctions in eating eggs. (however, it would be interesting to try).
The Chinese style is also the boiling of quail eggs in soy sauce, where the egg white turns dark brown (you may think the soy sauce has been diluted with water but not sure).