Pat dry the White Fish Fillets and roughly chop them, then pulse in a food processor (or mince very finely) until you have a coarse paste.
Finely grate or mince the Onion and squeeze out excess moisture with your hands or a paper towel to avoid a watery batter.
In a large bowl combine the fish paste with the onion, then beat in the Egg and stir in the Whole Milk to loosen the mixture.
Add the Wheat Flour, chopped Parsley, and season with Salt and White Pepper; mix until you have a thick, spoonable batter — it should hold together but still be soft. Adjust a little extra flour or milk if needed.
Let the mixture rest for about 10–15 minutes so the flour hydrates and the flavors meld.
Heat a skillet over medium heat and add a knob of Butter and a splash of Neutral Oil to prevent burning and help even browning.
Form the batter into oval patties with two spoons or lightly wet your hands and shape by hand, then place them in the hot pan without overcrowding.
Fry the cakes for 3–5 minutes per side (depending on size) until deeply golden and cooked through, flipping carefully so they keep their shape.
Transfer cooked fiskefrikadeller to a plate lined with paper towel to drain briefly, then serve warm.
