In a medium bowl, gently mix mangoes, tomatoes and parsley.
In a separate bowl, combine vinegar, sugar, salt, and pepper.
Pour over mango salsa, stirring lightly. Arrange steamed kangkong on a platter.
Spoon mango salsa over kangkong and serve.
You can also chill the kangkong and salsa for 10 minutes to make a cold salad.