Stuffing: Place the potato cubes in a medium saucepan and cover with cold water. Add salt and boil until potatoes are just tender and able to be pierced easily with a paring knife. Drain and place in a medium bowl. Add sausage, peppers, ground almonds, and 1/2 of the smoked paprika. Toss until well combined. Season to taste with black pepper.
Place the remaining 1/2 tablespoon smoked paprika in a small bowl, add olive oil; stir and set aside.
Place pork loin on a work surface. Starting at top, make a lengthwise incision down center of the loin, cutting two thirds of the way through thickness of meat (be careful not to cut all the way through). Open loin like you would open a book. Turning knife horizontally, cut tenderloin open on either side like the flaps of a book jacket, being careful not to cut all the way through.
Pour 2 tablespoons of the liquid that the peppadew peppers came in and pour onto the cut side of the pork, spread with a brush. Mound the stuffing evenly over meat from the center cut to the edge closest to you, leaving a 1-inch border.
Fold over the top half and press to seal.
Using kitchen string, tie at 1- to 1 1/2-inch intervals. Transfer pork to a rack on a foil lined baking sheet. Brush with the reserved paprika oil.
Let pork stand at room temperature 20 minutes before roasting. While pork comes to room temperature, put oven rack in middle position and preheat oven to 450 degrees.
Roast pork 25 minutes, then reduce oven temperature to 325 degrees, tent with foil, and continue to roast until thermometer inserted diagonally into center of meat registers 135 degrees, about 30 to 40 minutes. Transfer pork to a cutting board, tent loosely with foil and let stand 10 minutes before slicing.
(Courtesy of Maria Dittrich)