Cut the tomato in half (remove the stem), cut those halves in half and cut into equal pieces. You can dice them as small or as big as you prefer.
Cut the cucumber in half and slice each half into half moons. Cut the red onion into thin slices and add everything to a bowl with the kalamata olives.
In a separate bowl, add the feta and mash with a fork. Add in the oregano, red wine vinegar, olive oil, and dill (if using). Mix well.
Pour the creamy feta mixture onto the salad and toss. Taste and adjust for salt if needed and enjoy!