I made a big batch of these croquettes made with Sichuanese leftover tongue two weeks ago (click: recipe ). Only dusted them with flour and then froze them. Today I took some out, dipped them (still frozen) in egg white, then panko, then egg white and panko again and deep fried them for about 8 minutes at 180C. Dead easy! Almost as easy as buying ready-made croquettes, but much tastier! I think it was worthwhile the effort.