Boil eggs and cut into slices.
Cucumber and radish in half rings, grate feta cheese on a coarse grater.
Stir the olive oil and balsamic vinegar well.
Chop part of the onion finely, and the second part coarsely.
Cut the spinach not very finely, chop the rest of the greens as usual.
Mix everything and season with olive oil and vinegar.
