Much easier than I expected, mainly because there was no breadcrumb coating to fuss over.  I also simplified it by nuking the potatoes and then using the same bowl that they were cooked in to mash them and mix in all the other ingredients.  The fishcakes were fried, which I need more practice at frying.  I served them with curly fries, sweetcorn and baked beans.  Sam had ketchup, I had fruity HP and John had mango chutney.  They were very tasty, although a bit light on the fish. 
 Sam ate his, and liked them, and said I could cook them again.  Hannah wouldn’t touch hers.