Wash potatoes thoroughly and cook in boiling salted water for 18 minutes. In the meantime, clean and wash the peppers and cut them into small cubes. Clean and wash the radishes, cut them in half and put them aside for garnishing and cut the rest into sticks.
Finely dice the cucumbers. Mix mayonnaise and yoghurt, season with salt and pepper. Stir in diced vegetables. Drain potatoes. Heat oil in a pan and fry potatoes until golden brown, turning them over.
Season with salt and pepper. Arrange potatoes, aspic and tartar sauce on a plate and garnish with the remaining radishes. Garnish with salad leaves and basil as desired.