Description of the problem:

I'm referring to the Chinese pot roast tenderloin. It's the kind you make with an egg turnover spoon. I'm trying to find the source because I can eat it in Tianjin, but not in Beijing.

Analysis:

The earliest pot collapse series of dishes is from Shandong, as early as the Ming Dynasty in Jinan, Shandong Province appeared in the pot collapse tofu, this dish to the Qing Dynasty Qianlong years rose to the court dishes. The dish was then spread all over Shandong and introduced to Tianjin, Beijing and Shanghai. Later, it was improved in different places, such as silverfish in pot collapse, and loin in pot collapse, which is a unique practice in Tianjin.