Hi meine mum sagt das ich lernen soll Stullen zu essen und nicht mehr so picky sein soll was meint ihr?

These are very little background information. What exactly is meant by “stules”. And above all what’s in there/drauf?

Do you want to feed yourself on Stullen? Not acceptable. Will certainly lead to symptoms of deficiency or even diseases.

How old are you? From a certain age, you can also demand that funds be made available to you that you at least partially provide yourself. Buy yourself something and prepare yourself food. If your parents don’t want to do this.