Mix the mashed potatoes with a beaten egg and 6 tablespoons of flour. Form 3 balls with floured hands and press them flat. Spread 1 teaspoon of fried onions on top and place 1 slice of ham on top. Place 1/3 of the Gouda slice on each half of the nut ham and roll up the topped slice. Shape into a ball again and press flat. Make sure that the filling does not ooze out.
Heat a pan with the sunflower oil and butter. Fry the pancakes on each side until golden brown.