I believe the rule is that fish which is 1 inch thick should be simmered for no more than 10 minutes.
What about fish like anchovies, whitebait and sardines which I think are less than an inch thick. How long should they be simmered for in order to avoid overcooking?
What if the anchovies, sardines or whitebait are cooked from frozen(due to perishability), how long should they be simmered for in this case?