Thank you guys for being interested, yes it is pig liver Vaslin
but it was stir-fry cooked with thick flavourful soup
I don't know how to put it in words about the unique texture
and Tb, if you accept eating liver things I believe it is good option
it is called 炒肝(chao3gan1) and I didn't find it in other cities but only in Beijing
It was told to be a Beijing snack loved original Beijing People
but you have to find out a decent restaurant with high standard of requirement for sanitation and cooking process and in a cooler weather
forgot mention that you may find few small pieces of cooked intestines in the soup