In a small bowl, mix eggs,, water and salt with a fork until well blended.
Heat a frying pan on the stove top on high. Put 2 tablespoons of the butter in the pan. Slice the mushrooms and fry in the butter til brown.
Take the mushrooms out of the fry pan and add the remaining butter. Turn off the element and leave the pan on the hot element. Pour the egg mixture immediately into the pan. Swirl the mixture with a fork a few times.
Leave the egg cooking on the pan, spread the cooked mushrooms, capsicum, cheese and parsley over the egg.
After about 3 minutes, check base of the egg, it should be browning. You will need two spatulas to flip the egg in half to cover the Topping. Once you have done this, let it cook for another minute to warm all the way through. There should be no runny egg at this stage.
Flip onto a plate and enjoy!