After boiling three fresh wood-fired eggs, take out the egg yolks and crush them, put them in a clean iron pot and cook them slowly over a slow fire (a flame the size of a mung bean).

At the same time, use wooden chopsticks to stir the broken egg yolk gently until the egg yolk in the pot gradually turns black. Just be patient and don't give up.

When you smell a burnt smell, you will slowly find some liquid gradually appearing in the pot, about a small tablespoon, this is egg butter.