A traditional Chinese food. The recipe uses various spices, soy sauce, and black tea leaves. The eggs are boiled until they reach a hardened, cooked state, then the boiled eggs are removed from the water, and the entire shell of each egg is gently cracked all around. Smaller cracks produce more marbling, visible when the egg is peeled for eating. It's like snowflakes because no two are ever the same.
It is best to make it the night before, so you can let the eggs soak in the tea overnight in the refrigerator.