Hard Boiled But Soft Inside
Mottled Like Ancient Porcelain
“Tea eggs are one of those ways of hard-boiling eggs so long that they are soft inside.” — Buwei Yang Chao 
Tea Eggs, as Dr. Chao says, are a Chinese way of hard boiling eggs for a long time so that eventually they become soft again. Not soft-runny, but soft and dry-tender, as far as the yolks, and soft and firm but not leathery for the whites.
The Eggs are boiled with tea leaves and the shells are crackled but not removed. As a result, when you shell them, the Eggs are a mottled color like ancient porcelain.