Peel the cucumber skin in alternate strips as shown in the picture. This is not mandatory but adds to the visual appeal of the finished dish.
Cut the cucumber into thick circles; scoop out the seeded part in the centre leaving just a thin layer at the bottom to hold the stuffing.
Season the cucumber slices with salt, pepper and lemon juice. This also helps to draw out the excess water and firms up the cucumber a bit.
To prepare the filling, mix the eggs, tomatoes, herbs, mayonnaise and then sprinkle in the feta. Mix well to form a creamy texture; if you think the mixture is runny, then add more eggs or cheese to firm it up.
To assemble, line the cucumber pieces, fill with the stuffing and garnish with chives. Place in a platter and refrigerate till serving time.