Cooking for the brothers can be a daunting task, as can be eating their cooking at times. The moral excellence of friary cooking is a complex judgment, but I believe it can be narrowed to a function of four interacting values:
1. How talented and/or knowledgeable of a cook a brother happens to be,
2. How conscious and aware he is of 1., above,
3. Whether he puts effort into the meal, and
4. Whether he makes an inordinate mess, depending on local community standards.
Therefore, the best case scenario for friary dinner is when the brother cooking that day knows how to cook, knows that he knows how to cook, makes an effort at it, and cleans 'as he goes' so as not to make a big mess.
Beneath this best case scenario the situation grows far more complex. For example, the moral judgment on messiness depends somewhat on the other factors; brothers who make a great meal are often forgiven their messes, while those who prepare average or yucky meals are not. Conversely, an average cook is helped much by being clean.
The talent and knowledge that make a brother a good cook are not absolute either. A brother who doesn't know much about cooking but who masters one or two plain suppers will be appreciated far more than the good cook who doesn't make much effort to please.
The most dangerous friary cook is the brother who thinks he knows how to cook but in fact does not.