Bring a pan of water to the boil, add the eggs and simmer for 8 mins, then drain and cool under cold running water. Peel and chop the eggs, then tip into a bowl and mix with the mayo, yogurt, chutney, curry paste, spring onions and coriander. Season to taste. Butter the bread and spoon the egg mixture over two slices. Complete the sandwiches with the remaining bread, then halve.