In a pot, combine the jin-ganjang, cooking wine, tuna sauce, dark brown sugar, minced garlic, corn syrup, anchovy stock powder, and water, then stir well to make the braising sauce.
Rinse the quail eggs once under running water and set them aside.
Chop the onion into small pieces and have the whole garlic cloves ready.
Bring the sauce to a boil over high heat.
Once the sauce starts boiling, lower the heat, add the quail eggs and garlic cloves, cover with a lid, and simmer for 10 minutes.
After 10 minutes, remove the lid, add the onion and peperoncino, and simmer for another 10 minutes over low heat.
Finally, pour in the starch slurry and stir well to adjust the sauce to your desired thickness.
To make the starch slurry, mix 0.3 T of starch with about 1 T of water.
Finish by generously sprinkling toasted sesame seeds on top.