Whisk together red curry paste, fresh lime juice, and 1 large egg in a medium bowl. Stir in 1/2 cup whole-wheat panko, chopped scallions, chopped fresh cilantro, and kosher salt. Add peeled, deveined, and chopped raw large shrimp; stir well to combine. Divide mixture into 4 equal portions; shape each into a ball. Place 1/2 cup whole-wheat panko in a shallow dish; roll balls in panko to adhere. Heat a large nonstick skillet over medium. Add canola oil. Add balls to skillet; using a spatula, flatten each to a 1-inch-thick patty. Cook until browned and cooked through, 3 to 4 minutes per side. Serve over Bibb lettuce leaves, if desired.