3 medium cucumbers, peeled and sliced 1/4 inch thick1 medium onion, sliced and separated into rings3 medium tomatoes, cut into wedges1/2 cup vinegar1/4 cup sugar1 cup water2 teaspoons salt1 teaspoon fresh coarse ground black pepper1/4 cup oilCombine ingredients in a large bowl and mix well.Refrigerate at least 2 hours before serving