Prep the produce. Wash and dry the lettuce leaves and set aside.
Dice the onion, carrots, and bell pepper; mince the garlic; grate the ginger; chop the water chestnuts; slice the green onions.
Make the sauce. In a small bowl, whisk soy sauce, hoisin, rice vinegar, sriracha, and honey. In another small cup, mix cornstarch with water to make a slurry. Keep both nearby.
Brown the turkey. Heat sesame oil in a large skillet over medium-high.
Add turkey and break it up with a spatula. Cook 4–6 minutes until no longer pink. If there’s excess liquid, spoon it off for a cleaner, less watery filling.
Sauté aromatics. Add onion, garlic, and ginger to the turkey.
Cook 2–3 minutes until fragrant and the onion softens.
Add veggies. Stir in carrots, bell pepper, and water chestnuts. Cook 2–3 minutes, just until tender-crisp. You want them to keep their crunch.
Sauce it up. Pour in the sauce and stir to coat.
Once it bubbles, add the cornstarch slurry and cook 1–2 minutes until slightly thick and glossy. Stir in green onions. Taste and adjust salt, heat, or sweetness as needed.
Assemble. Spoon warm turkey filling into lettuce leaves.
Top with cilantro, sesame seeds, and a squeeze of lime. Add more sriracha if you like it spicy.
Serve immediately. Enjoy as a light meal or appetizer. Two to three lettuce cups make a nice serving for lunch; four to five for dinner if you’re keeping it low calorie.