Place whole potatoes in cold salted water, bring to the boil and simmer for 30 minutes.
Meanwhile grind coriander, cumin and peppercorns in spice mix.
Mix in a bowl with yogurt and finely chopped coriander stalk. Season with salt.
Remove potatoes, strain in a colander and place on a tray in the fridge.
Once cool enough to touch, slice into 1/2cm ring pieces.
Place in a bowl and add your desired amount of yogurt dressing.
Roughly tear up the coriander leaves and fold through. Check the seasoning.
Serve on a platter.
TIP: Add a little vinegar to the water when boiling the potatoes. The vinegar causes the potatoes to form a thin crust, which helps them hold their shape.