Bring 3 cups water to a boil in a saucepan and remove from heat. Stir in barley and return to heat. Return to a boil, reduce heat and cover, simmering for 30-40 minutes. Barley will be done when it is tender, but still chewy. Drain remaining liquid and return the barley to the pan. Cover and allow the barley to steam, off the burner, for about 10 minutes. Meanwhile, mix the olive oil, red wine vinegar, salt and pepper. When the barley has steamed, dress it with the olive oil mixture. (Dressing the grain while it is hot will allow it to absorb more of the vinaigrette.) Refrigerate overnight, or until completely cool. Add grape tomatoes, cucumber, basil and red onion and toss. Adjust seasonings. Six servings, each serving providing one teaspoon of healthy oil.