Place the shrimp, egg white, onion, cilantro, cayenne, soy sauce, ginger, garlic, creole seasoning, salt and 1 /2 teaspoon of the sesame oil in a food processor and pulse 2 or 3 times to finely chop. Do not puree.
Put egg yolk, remaining 2 tablespoons sesame oil, vinegar, soy sauce, sherry and water in a shallow bowl and whisk to blend.
Spread equal amounts of the shrimp mixture.
Heat 3 tablespoons vegetable oil in a large nonstick skillet over medium-high heat. Dip toasts in egg mixture, coating evenly on both sides. Place them a few at a time, shrimp side down first and fry until golden brown, about 4 minutes on each side. Remove from the skillet. Repeat the process with the remaining 3 tablespoons vegetable oil and toasts.
Serve with the shrimp side up.
Slice each sandwich into 2 triangles, place on a serving plate and garnish with parsley