In bowl of food processor, add shrimp, egg, cilantro, scallions, green chilies, garlic, ginger, sesame oil, salt, brown sugar, lime juice and cornstarch. Pulse until smooth.

On work surface, lay out bread slices and spread generous spoonful of shrimp mixture over each slice, pressing gently to adhere. Sprinkle sesame seeds on top and lightly press into surface.

Heat about ½-inch of oil in skillet over medium heat. Once hot, place toasts shrimp-side down. Fry 2-3 minutes until golden and crisp, then flip and fry bread side for 1-2 minutes. Transfer to paper towels to drain.

To make spicy mayo, in small bowl, combine mayo, sriracha and garlic powder, if using. Stir until smooth.

Slice each toast into halves or quarters. Serve warm with spicy mayo on the side.