In a small bowl, combine the onion and sugar, add cold water to cover and set aside for 15 minutes.
Drain, then rinse under cold water. Drain again, shaking to remove the excess water. Pat dry.
In a medium bowl, toss the onion with the parsley, jalapeno, radishes, cilantro and chives.
Add the oil and lemon juice and season with the coarse salt.
Spoon 2 teaspoons of the salsa onto each piece of salmon and roll up into a cone.
Set each cone on a piece of toast, then arrange on a platter and serve.