Peel cucumber and cut in half lengthwise. With a small spoon, scrape out seeds and discard, then cut cucumber into bite-size chunks

Place in a large bowl and combine with tomatoes, green pepper, onion, feta and olives.

In a small bowl, combine oregano and vinegars and whisk in olive oil. Drizzle half the dressing over the salad and season with salt and pepper.

Serve with remaining dressing on the side. May serve over lettuce greens if desired.