Wash the potatoes and cook for 20-25 minutes until soft. Bring stock and vinegar to the boil. Drain potatoes, rinse briefly under cold water, peel and cut into thick slices. Add stock and vinegar to the potatoes. Let the salad stand for 1-2 hours. Blanch peas in boiling salted water for about 2 minutes, then rinse under cold water. Clean and wash the radishes and cut them into small slices.
Put the corn in a sieve and let it drain. Clean, wash and cut spring onions into rings. Mix yoghurt and mayonnaise, season with salt and pepper. Fold radishes, peas, corn, half of the spring onions and yoghurt sauce into the potatoes. Season salad again with salt, pepper and possibly a little vinegar. Sprinkle the rest of the spring onions on top
1 hour waiting time