Sorry I am not totally sure still. This is my best guess. "I don't like this lasagne - what did you do to it?" This means that you cooked the lasagne. It tasted bad so I am asking how you cooked it so badly. I don't really want to know your answer - it's just a way of expressing naturally that there is something wrong with it. Is this what you mean?

I am sorry no-one has helped you with this. I know some Spanish but this phrase doesn't make sense to me if I translate it literally (to have done / made it, you). Can you say the same phrase in a different way and we can try again? Saludos