Dice the red onions while they are still on the chopping board sprinkle the mixed spices on top so the spice sticks to the onions; add to a large salad bowl. Dice the cucumbers & cut the cherry tomatoes in half add to the bowl. Add the olives & torn mint leaves & mix together. Add the oil, lemon juice & salt & pepper to taste, mix together. Cut the feta into cubes & toss through the dried oregano add the feta to the top of the salad & serve.