Heat the water in a pot. When it starts boiling, add the salt and sugar. Stir until melted and then remove the syrup from the heat.
Add the melted chocolate and beat well with a mixer. Gradually add the butter and beat well again. Lastly, add the eggs, beat once more with a mixer.
Bake the prepared mixture in a water bath in a preheated 356°F (180 °C) oven. Bake for about 45 minutes or until ready.
Leave it overnight to cool well and then remove it from the oven dish.