In a mixing bowl, whisk the first seven ingredients together. Season with dressing with salt and pepper. In a mixing bowl, mix the nuts, seaweed, peppers, and onions together. Add the ahi and remaining sesame oil. Mix the salad very well. Season with salt and pepper. To assemble, lay the radicchio in the center of a platter. Pile the salad in the center of the radicchio. Drizzle the sauce over the salad. Garnish with long and chopped chives.