Whisk lemon juice with water and 1-2 teaspoons of olive oil. Finely dice the onion and ginger and mix into the marinade. Season to taste with salt, pepper and sugar.
Peel the avocado, cut in half, remove the stone and finely dice the pulp. Carefully fold into the dressing, season again to taste.
If you like, you can sprinkle 1 tablespoon chopped coriander on top.
It goes well with fresh baguette or pumpernickel.
Don`t take limes, I tried that too, but then you can`t taste the avocado anymore.