"For those short on breaded fish (& the resources to cook it), remember bread &/or breaded fish may drop from the Dairy Trade in the Royal Exchange as well as from the following items, if you have them:
Bread:
*Harvest Pergola
*Ivy's Bakery
*Summer Gazebo
*Ye Olde Bar 'n Grille
*Sir Pigglesworth
*Parrot (rare)
Breaded Fish:
*Harvest Pergola
*Ivy's Bakery
*Sir Pigglesworth
*Fish Market (very rare)
There is also a chance for both of those to drop from Feed the Baron (I think), but it's rare, too." ~North Woods
If you have the resources for Cook With Glimmermouth, it usually gives a few breaded fish along with other fish dishes.