we adore the idea of a self funded recipe book .. it’s something the Broadstairs Food Festival would love to explore with loca chefs and festival exhibitors.
I have made kroppkakor for over 60 years and found it better to use an Idaho potato and then squeeze the water out of the grated potato – retain the water squeezed out. Let this set for a short time and take some of the starch that collects on the top of the water and add back to the mixture with the flour. It helps hold the balls together and they are not as wet. I have also learned to fry the meat and onion just a little prior to making the balls.
As noted, leftovers that have been kept in the ref, can be sliced about 1/2 to 3/4 inch thick and fried in butter or marg. May need to sprinkle a little allspice on these to get the best flavor.