Prep the produce: Rinse and separate the lettuce leaves. Dice the onion and bell pepper.
Mince the garlic and ginger. Slice the green onions, keeping whites and greens separate.
Mix the sauce: In a small bowl, whisk soy sauce, hoisin, rice vinegar, sesame oil, sriracha, honey, and black pepper. Taste and adjust for sweetness or heat.
Cook the aromatics: Heat the oil in a large skillet over medium-high heat.
Add onion, bell pepper, and the white parts of the green onions. Cook 3–4 minutes until softened. Stir in garlic and ginger for 30 seconds until fragrant.
Brown the turkey: Add the ground turkey.
Break it up with a spoon and cook 5–7 minutes until no longer pink and lightly browned. If excess liquid appears, let it cook off for better flavor.
Add crunch: Stir in the diced water chestnuts, if using. Cook 1 minute to warm through.
Sauce it up: Pour the sauce over the turkey mixture.
Stir and let it simmer 2–3 minutes until glossy and slightly reduced. Turn off heat and fold in the green onion tops.
Assemble: Spoon the warm turkey filling into lettuce leaves. Top with carrots, cilantro, crushed peanuts, sesame seeds, and a squeeze of lime if you like.
Serve: Bring the skillet to the table with a plate of lettuce cups and toppings.
Eat right away for the best crunch.