"Asian flavors and avocado play well together in this open faced sandwich. Instead of arugula you can use mixed baby greens. And you can replace the fish fillet with a steak or burger. For a variation, try the aioli over cooked shrimp or crab."
In a medium bowl, combine avocado, vinegar, ginger and salt. Mash with fork. Stir in cilantro. Cover tightly by pressing plastic wrap directly on to the surface of the aioli to prevent discoloration. Set aside while grilling salmon.
Brush salmon or halibut fillets with 2 tablespoons of the olive oil. Grill or broil for 3 to 4 minutes per side, turning once.
Brush remaining olive oil on bread slices and grill or toast.
Arrange half cup arugula on each toast slice. Top with salmon fillet and one quarter of the avocado aioli. Drizzle with hoisin sauce and sprinkle with toasted sesame seed.