Cut cucumber into cubes. Cut the colourful tomatoes in half.
Put everything into a large salad bowl. Peel the red onion and cut into fine rings.
Dice the feta cheese. Add the onions, feta and the black olives to the bowl.
Now add olive oil, salt, pepper oregano and a bit chili oil to spice things up.
Mix everything together and let the salad rest for about 15 minutes before serving!