Peel 14 oz of the potatoes (about 7/8 cup) and boil them in salted water for approximately 20 minutes or until soft. Grease the loaf baking pan or line with parchment paper, leaving excess paper hanging over the sides for easy removal of the finished cake. Preheat the oven to 200°C (175°C fan oven) or about 390°F.
Meanwhile, peel and dice the onions. In a pan, render down the bacon and lightly braise the onions with it.
Let the cooked potatoes cool down a bit. Pass through a potato ricer to mash them.
Peel, wash and roughly grate the remaining potatoes.
Knead the grated and cooked potatoes together with the onion-bacon mixture, cream, eggs and a few generous pinches of salt, pepper and nutmeg.
Add the dough to the prepared baking tin. Bake for 50-60 minutes. Cool before removing from the pan, either by turning it over or carefully taking it out with the parchment paper. Then cut into slices.
You can either eat it straight away, or reheat slices by frying them in a pan until brown and crispy on both sides.