Place the bulghur in a bowl or pan and pour in enough cold water to cover it completely. Let it soak for about 10 minutes, then drain in a sieve or colander lined with a double thickness of dampened cheesecloth. Wrap the burghul in the cheesecloth and squeeze it vigorously until completely dry. Drop the bulghur into a deep bowl, add the tomatoes, parsley, onions, lemon juice and salt and toss gently but thoroughly together with a fork. Just before serving, stir in the olive oil and mint and taste for seasoning. Mound the salad in a serving bowl or spoon it onto romaine lettuce leaves.