Crumble the rice cakes and mix them in a bowl with tomato juice. Leave to stand for about 15 minutes.
In the meantime peel and finely dice the onions. Wash the chives, shake dry and cut into small rolls. Lightly mash the rice wafers with a potato masher. Mix the onions into the rice cakes.
Season to taste with soy sauce, salt, pepper and Tabasco. Pour into glasses and sprinkle with chives. Keeps for about 4 days in the refrigerator.