You can pre-order it from the Chinatown butchery.
Maybe it does not sell well and really perishable so not every
store carries the product.
Even the Italian eats pig's lung, I saw it at Italian markets
What do you do with cooked pig's lung?
it is usually for soup with bok choy and dried bok choy,
almond and bitter almond. Good remedy for chronic coughing.
I never use it for other cooking,
unlike beef lung which is more versatile.
I know some Italian would make pig'd lung Hunter style,
Cacciatore, garlic, tomatoes, wine, olive & chilli,
spicy and tasty, very inexpensive and filling for family meal
Usually they would insert the water hose to the cord of the lung,
let the water runs for half an hour then squeeze out all the water.
The soup taste good thou.