Wash and dry lettuce leaves carefully so they hold shape. Trim any thick ribs so leaves form cups. Finely chop onion, celery, carrot and red pepper; mince garlic and grate ginger. Slice green onions and pick cilantro leaves.

In a small bowl whisk together soy sauce, oyster sauce, rice vinegar, sesame oil, hoisin (if using), chicken broth (or water), and cornstarch until smooth. Set sauce aside.

Cook Filling

Heat pan

Heat a large nonstick or wok-style skillet over medium-high heat. Add vegetable oil and swirl to coat.

Cook aromatics

Add chopped onion, celery, carrot and red pepper to the hot pan. Stir-fry 3–4 minutes until softened but still a little crisp.

Brown chicken

Add ground or diced chicken to the pan. Break apart with a spatula and cook 4–6 minutes until no longer pink, stirring frequently so it browns lightly.

Add garlic & ginger

Stir in minced garlic and grated ginger and cook 30–45 seconds until fragrant, taking care not to burn.

Add sauce & finish

Give the reserved sauce a quick stir and pour into the pan. Stir constantly as sauce thickens—about 1–2 minutes. If mixture seems dry, add up to 1–2 tablespoons water or broth. Taste and adjust seasoning with black pepper and salt as needed. Remove from heat and stir in half the green onions and half the cilantro.

Assemble

If using crispy pastry cups, warm them briefly in a 325°F (160°C) oven for 3–5 minutes until crisp. Spoon about 1–2 tablespoons of the chicken mixture into each lettuce leaf or into pastry cups. For each wrap, top with a small pinch of crispy fried noodles for crunch, a sprinkle of remaining green onion and cilantro, and a squeeze of lime.

Arrange assembled lettuce wraps on a platter. Serve immediately with extra lime wedges and optional red pepper flakes on the side.