Wash and dry the mixed greens thoroughly.
Halve the cherry tomatoes and place them in a large mixing bowl.
Dice the cucumber and add it to the bowl.
Slice the bell pepper into thin strips and add it to the bowl.
Thinly slice the red onion and toss it into the bowl.
Add the Kalamata olives and crumbled feta cheese to the mixture.
In a small bowl, whisk together olive oil and red wine vinegar.
Season the dressing with salt and pepper to taste.
Pour the dressing over the salad and toss gently to coat.
Serve immediately, garnished with additional herbs if desired.