In addition, I'll tell you a special product of Shangqiu, "Slag Cake", which can't be bought. It is made of mung bean rock crushed in a flat pot. It is usually eaten during the Spring Festival. Generally speaking, old people like to cook this dish because it is delicious. But now young people rarely do it because its technology is more complicated. Most products on the market are made of corn flour, and the taste is very different from that of soybeans. Want to eat authentic "dregs cake",