I dreamed that my dead mother-in-law died, and then I put her in a pot to cook. When she cooked, I used it to eat. I put a large piece of human flesh in my mouth and stuck it in my throat. ...

From a psychological point of view, the reason why you have such a dream should be that you are somewhat dissatisfied with your mother-in-law.

Cooking a person in a pot and eating her meat shows that you have a lot of resentment against this person and are eager for revenge.

If you get stuck in your throat and spit it out, it means that you have some remorse for your revenge.

However, the dead are gone. Let bygones be bygones, don't dwell too much on the past.