In a small bowl whisk together soy sauce, oyster sauce, rice vinegar, sesame oil, mayonnaise and sriracha until smooth and slightly emulsified. Set aside.

Sauté aromatics

Heat a large nonstick skillet over medium-high heat. Add vegetable oil and swirl to coat. Add minced garlic and ginger and cook, stirring, 30 seconds until fragrant but not browned.

Cook shrimp and vegetables

Add the rock shrimp to the skillet and spread into a single layer. Let cook undisturbed 1 minute to develop a little color, then stir. Add diced red bell pepper and the white parts of the scallions. Cook 2–3 minutes more until shrimp are opaque and cooked through (total cooking time will be ~3–4 minutes depending on size).

Finish filling

Remove skillet from heat. Pour the prepared sauce over the shrimp and vegetables and toss to coat evenly. Immediately add mayonnaise mixture will warm slightly and create a saucy glaze. Stir in chopped cilantro (if using). Taste and season with kosher salt and freshly ground black pepper, adjusting sriracha or salt as needed. If filling seems too wet, cook over low heat 30 seconds to reduce slightly.

Assembly & Garnish

Arrange butter lettuce leaves on a serving platter, cupped side up. Spoon about 2 to 3 tablespoons of the warm rock shrimp filling into each leaf (adjust amount to leave room for garnishes).

Top each filled lettuce cup with a small pinch of julienned cucumber and carrot for crunch and freshness.

Sprinkle toasted sesame seeds over the cups and scatter remaining sliced green parts of scallions for color and bite.

Serve immediately with lime wedges on the side for squeezing. Encourage diners to pick up a whole leaf, squeeze lime, and eat as a handheld cup.