My mother-in-law always cooks dishes that have been left for a long time. Sometimes some rotten dishes are cooked by our family, and sometimes they are said to be newly bought. What should I do?

According to what you said, I think your mother-in-law probably didn't lie or do anything. That's her habit. She probably thought that the food she bought for two or three days was fresh, so she always said it was new. At home, she just uses cooking oil repeatedly, just like my parents. People of that age have experienced hard times since childhood, and they don't talk about health. It's all about saving money and reusing things. But this kind of repeatedly used oil is really bad, because there will be food paste residue after food frying, which cannot be removed, and this paste residue is a carcinogen, which does not mean that it will definitely cause cancer, but it will increase the probability of cancer. People didn't have this knowledge before, so they all ate and used it like this. Now there is research in this field, and we should try to avoid eating this oil. As for whether the meat and vegetables are fresh or not, I believe your mother-in-law because that's what she thinks is fresh. ////Everyone upstairs, don't always attribute the problem to your mother-in-law, not your mother. There is such a situation, but obviously this mother-in-law has no malice. This is because her daughter-in-law loves to have grandchildren, so she always comes to help with the kitchen, but she is unlucky and pats her legs. This kind of problem should not depend on the mother-in-law being bad to her daughter-in-law. It's just that understanding and habits are different.