Shepherd's Purse and Tofu Soup

It's funny how you can eat something all your life and never know what it's called. There's this particular vegetable native to Shanghai that I've literally been raised on from my mom (being a Shanghainese-raised girl herself). To me, it's always been known as Ji Tsai. They only come frozen here in California, and the label always says "Chinese water spinach". However, I know that Chinese spinach is really kongxing tsai or onchoy, which is a completely different vegetable.

Yesterday I finally figured out what this mystery plant's English name is! It is called "shepherd's purse", which is the weirdest name I have ever heard. Did ancient Shanghainese shepherds collect them in their purses? Were there even shepherds in Shanghai? Hard to imagine in such a metropolitan city.

Anyway, Mom made this soup with Shepherd's Purse, Tofu, and re-hydrated Shiitake mushrooms. She also added some diced pork meat and shrimp, as well as water chestnuts (not in the original recipe - it was left over from something else), chicken broth, and a lot of cornstarch. As a result, it's sort of a soup, but very thick - almost like a stew. She calls it "Ji tsai doufu gong".

I'll see if I can post the recipe up. I know how to make it, but I've never really measured anything out before, seeing as I learned it just from watching as a child from my mom.