Soak rolls in water. Wash potatoes thoroughly and cut them in half lengthwise. Coat baking tray with 1-2 tbsp. oil and sprinkle with coarse salt and 1-2 tbsp. herbs. Place potatoes with the cut surface on top.
Bake in a hot oven (electric cooker: 175°C/circulating air: 150°C/gas: level 2) for about 40 minutes.
Peel and chop the onion. Squeeze out the buns. Knead both with minced meat, egg, mustard, 1 tablespoon herbs, salt and pepper. Form 20 balls with moistened hands. Fry in 2-3 tablespoons of hot oil all around for about 8 minutes.
Finely crumble feta for the dip. Mix with mayonnaise, yoghurt and "Dip Quick" seasoning mixture. Remove meatballs and potatoes. Skewer one ball onto each potato half.
Garnish with feta dip and basil.