ran-ou no misozuke (卵黄 の味噌漬).
They are egg yolks, pickled in miso. It’s a popular delicacy to enjoy as a salty snack with sake, or on your hot rice.
I have used eggs from the butcher’s… Well, they sell the eggs found inside the hens, that have no shell yet. They are excellent. Whenever my grandma would kill a hen, I was volunteering for the job (everything but the fatal stroke) and in exchange, the eggs were my lunch. In some places in Italy, they use them to make premium pasta. These are covered with a skin, which makes them easier to smear with miso, they don’t break. Also, I don’t need the whites.
The recipe can be done with standard yolks. For instance, see Shizuoka Gourmet’s technique for tamago misozuke.
1 cup of miso, 1 tbs of mirin, 1 tbs of sake. I just place the eggs with miso all over, cover and keep in the fridge. You can use any color of miso.
After 24 hours, the small ones are done. The big ones will mature in a few more days. I can eat them progressively.
You can take out the outer skin. The yolk is solid. Serve only one per person. I have more because they are minis. It’s delicious. Try it some day.