I know some do not eat fish and dairy/milk together. If an Ashkenazi Jew eats milk and cereal and then ice cream, is there a waiting period before fish? Must one rinse the mouth and eat bread or something else pareve inbetween? What about between fish and milk?
Thank you for your question.
The Ashkenazi minhag is that it is permitted to eat fish and milk even if they were cooked together such as a tuna casserole with cheese. Therefore there is no need to wait or rinse your mouth out etc.
Taz Y:D 87-3, Shach Y:D 87-5.