Cure raw yolks in a soy sauce mixture until they are just firm. The high concentration of salt in the curing liquid draws water from the exterior of the yolk, forming a thin, intensely savory exterior shell around a gooey, runny interior.
Here is a delicious mushroom preserve based on the Italian "Sott'olio" technique. The mushrooms are salted and pickled before preserving under oil. They can be flavored numerous ways. It's a great way to enjoy mushrooms for months to come!