In a large mixing bowl, combine the mayonnaise, cilantro, garlic, onion, and celery, mix well, and season with salt and pepper, fold in the potatoes carefully so as not to break them up. Season again with salt and pepper. Cover and refrigerate for 1 hour.
Season each fillet with salt and pepper, then dredge each in the sugar, tapping, off any excess. Heat the olive oil in a large sautÈ pan over medium-high heat. Add the fillets and cook until the sugar caramelizes, 2 to 3 minutes on each side.
To serve, place the potato salad in the center of a serving plate. Lay the salmon on top of the salad, and garnish with cilantro and parsley sprigs.
Yield: 8 servings