In a bowl, add peeled, de-seeded and sliced cucumbers, halved cherry tomatoes, halved Kalamata olives and crumbled feta. In another medium bowl, add red wine vinegar, salt, dried oregano and grated garlic. While whisking, slowly add in olive oil, until the dressing is thickened and creamy. Add desired amount of dressing to your salad and gently toss. Then add pickled onion, fresh mint and more feta to garnish. Serve and enjoy!