Place the tomatoes in a large bowl, pour over boiling water and allow to stand for 1 minute. Drain and peel away the skins. Slice the tomatoes and arrange on a large shallow serving dish. Sprinkle with the sugar, a seasoning of salt and pepper, the strained lemon juice, Worcestershire sauce and plenty of washed finely chopped parsley and mint. Leave to marinate for 30 minutes. Then toss and serve.