Marinated Tomato and Cucumber Salad

1/2 cup white-wine vinegar3 tablespoons sugar1 tablespoon olive oil1 teaspoon dried basil 1/4 teaspoon salt 1/8 teaspoon black pepper3-4 medium tomatoes (for about 2 cups chopped)2 large cucumbers (for about 2 cups chopped) 1/4 purple onion (for 1/2 cup finely chopped)In a small jar with a lid, mix together the dressing: vinegar, sugar, oil, basil, salt and black pepper. Cover and shake well. Set aside.In a medium bowl, dice the tomatoes, catching as much of the juice as possible. Peel, seed and dice the cucumbers, adding them to the bowl with the tomatoes. Peel and finely chop enough of the onion to make about 1/2 cup, adding it to the bowl as you chop.Drizzle the dressing over the vegetables and toss to coat well. Cover tightly with plastic wrap, and refrigerate for at least 4 hours and up to 24 hours before serving. Refrigerate, covered, for up to 3 days.Serves eight.Nutrition values per serving: 50 calories, 2 g fat (trace amount saturated), 8 g carbohydrates, 1 g fiber, 1 g protein, 0 cholesterol, 78 mg sodium.