First of all rinse and drain the watercress. Now, remove their stems and arrange a bed of watercress sprigs in a large serving platter or a salad bowl.
Now, peel the two kiwi fruits and cut them into fine slices. Assemble the kiwi slices on the top of the watercress.
Scatter the thinly sliced mushrooms and tomato slices on top. Cover and refrigerate this mixture until you make a filling and smooth vinegar-olive dressing.
Pour the red wine vinegar into a small mixing bowl and season with some fresh ground black pepper and salt. Whisk both of the ingredients together until smooth and the salt dissolves completely. Add in the olive oil and fluff up again until it mixes up with the mixture.
Few seconds prior to dishing up, drizzle the dressing all over the salad mixture and mix up very gently, making sure not to disturb the arrangement of the ingredients of salad.