Xi'an is my favourite city in China for food. Not my favourite Chinese cuisine*, but favourite city. I lived there for a while in the 1990s and have returned many times since.
It is almost bang in the centre of China, was the Tang dynasty's capital and was the starting point of the Silk Road. As a result, it has absorbed and developed its cuisine from all over China and beyond. Also, it has a large Muslim population which has hugely influenced the cuisine.
Luckily, I have an excellent Xi'an restaurant near my home owned and staffed by Xi'an natives so I don’t go without.
I'll try to post as much about its many dishes as I can.
* That is Hunan cuisine – especially in the west of the province.