Put the eggs in a pot and cover with cold water. When the water is just coming to the boil, reduce heat and simmer 8 minutes. Cool and peel.
For the dukkah:
Roast the hazelnuts in a preheated 180 degrees C oven until golden. Rub them in a tea towel to remove the skins, then place in a food processor or spice grinder with the sesame seeds, cumin and coriander. Grind until a little coarse and season with salt.
To serve:
Cut the cucumbers and radishes into small pieces, arrange on a plate and sprinkle with salt and olive oil. Peel the eggs and serve with the olives and a bowl of dukkah for dipping.