Peel and dice the potatoes into large pieces. Place them in a large pot of cold water and bring to the boil. Once potatoes are cooked, drain them and leave until cool enough to handle, but still very warm.
Mash the potatoes in the pot and transfer the mash into a large bowl. Add the butter and mix it into the potatoes. Add salt and two thirds of the flour, and mix well again. Keep adding as much as you need of the remainder of the flour so that the dough is no longer sticky.
Turn your dough out on to a floured surface and roll out to 5mm in thickness. Cut into squares (or any other shape, or use cookie cutters if catering for kids).
In a large heavy based pan, heat the rapeseed oil and butter. Over medium heat cook the potato pieces until golden, turning them every now and again.
Prepare Salmon Spread
Using your fingers or two forks, break the salmon into small flakes over a bowl. Add cream cheese, cream, lemon juice and dill, and mix until combined. Test for seasoning and add salt and pepper if needed.
Spoon into a right-sized serving bowl and leave in the fridge for an hour for the flavours to fuse together. Serve it with the potato bread and perhaps garnishes like cucumber slices and parsley.