Mashed Potato Cakes | Cook's Country. water 1" over potatoes, boil 8-10 min until done, drain, let sot 10 min, mash in all but whole eggs, sour cream & panko, refrig for 1 hour, make 8 3" x 3/4" discs, dredge in egg then panko, sit 10 min, fry in 1/2 cup oil per batch of 4 (new oil for 2nd batch) 3 min on 1st side, 2 min on 2nd side, serve with sour cream.