Coarsely grate the cervelat and potatoes using a roesti grater, mix well with the salt and curry powder. Heat the butter in a non-stick frying pan. Add the potato mixture, fry for approx. 5 mins., stirring occasionally. Shape the roesti into a cake. Continue to fry the roesti (uncovered) over a medium heat for approx. 10 mins. until a golden crust forms. Place a large, flat plate on top of the pan. Tip the roesti out onto the plate. Add a little butter to the pan, slide the roesti back into the pan with the uncooked side facing down, finish cooking (uncovered) for approx. 10 mins.
Heat the butter in the same pan. Crack the eggs one at a time, slide into the pan, fry over a low heat until the egg whites are set but the yolks are still runny, season. Serve the fried eggs on top of the roesti.