Hard boil the eggs, using your favorite method. Cool slightly and peel. Cut them in half lengthwise.
Melt the butter in a frying pan and saute the onion and garlic, until onion is just soft.
Stir in the curry powder, tomato paste, water, lemon juice, salt and pepper. Allow the mixture to cook over a low heat until it is just bubbling.
Add egg halves to onion mixture and stir gently, until reheated through. Add a little more water if sauce gets too thick.
Add lemon zest and parsley. Stir again and serve while hot.
