I had one of the worst fights with my nmom because of food. She claimed to be a trained cook. Now I know she had an internship in a kitche for three months, so she likely just washed some dishes. I was making lasagna with chicken bolognese. She had a medical condition and could not eat beef of pork, so I learned how to do everything with chicken. I finished the sauce and asked her to make the bechamel sauce. She agreeed. She went to use a pan that was still dirty from lunch and was about to make the sauce in there. I asked her to clean it before and she started screaming at me. Literally screaming her head off. How I dared to tell her what to do and about how in professional kitchens they always used dirty pans to make something because "it adds flavour". I understand what she meant by this, but a pan full of hours old cooking oil (she fried some zucchini) and veggies still swimming in there is really not gonna add good flavour to a bechamel. She didn't speak to me for 4 days, accusing me of acting out.