Shio Yudetamago (Japanese Salted Boiled Eggs with Shells On)
Shio Yudetamago is a popular Japanese snack commonly found in convenience stores across Japan, and it just might change how you think about boiled eggs. By seasoning the eggs while they are still in their shells, you can enjoy a uniquely mild and salty flavor.
Put the water and salt in a Ziploc bag and mix well until the salt is dissolved (it's okay if it doesn't dissolve completely). Place the Ziploc bag in the refrigerator and let it chill for about an hour.
Fill a large pot with plenty of water and bring it to a boil. Once boiling, reduce the heat to medium and carefully lower the eggs, straight from the refrigerator, into the pot one at a time using a slotted spoon or ladle. Let them cook for 7 minutes for a soft-boiled consistency, or adjust the time to your preference.
Take the Ziploc bag out of the refrigerator. Once the eggs are cooked, remove them from the pot and place them in the Ziploc bag while still hot, then seal it. After the eggs have cooled, place the Ziploc bag back in the refrigerator and let it sit for 12-18 hours.
Notes
You can store it in the refrigerator for up to 2 days with the shell still on after removing it from the Ziploc bag. If it is hard-boiled, it can be kept for up to 3 days.