Cut the tomatoes into chunks and the cucumber into half-moon slices. Peel the red onion and slice it into thin rings. Place everything in a large bowl and add the olives.
In a small bowl, mix the olive oil with the red wine vinegar, a little dried or fresh oregano and freshly ground black pepper. Pour this dressing over the vegetables and toss gently together.
Break the feta into large chunks and place on top of the salad. Sprinkle with a bit more oregano. The combination of fibre-rich vegetables, healthy fats from the olive oil and protein from the feta makes this a satisfying lunch that supports your hormonal balance.