Wash the potatoes thoroughly and cook in boiling water for about 20 minutes. In the meantime, clean and wash the spring onions and peppers. Cut spring onions into rings, peppers into pieces and cabanossi into slices.
Peel the garlic and press it through a garlic press. Dice the feta cheese. Stone half of the black olives. Cut two green olives into slices. Mash the rest of the green olives, garlic, feta cheese and pitted black olives.
Stir in yoghurt and olive oil and season with salt and pepper. Drain the potatoes, rinse and peel. Slice the potatoes and let them cool down a little. Mix potatoes, spring onions, bell peppers and cabanossi and arrange on a plate.
Spread the yoghurt-cheese sauce over it and serve sprinkled with the olive slices and the remaining black olives. Garnish with basil as desired.