Heat a skillet over medium heat. Add garlic and cook until fragrant (30 seconds). Stir in chicken, soy sauce, and lime juice. Cook until chicken is fully cooked through and tender.
In a bowl, whisk together peanut butter, soy sauce, lime juice, and water until smooth. Add more water if needed (up to 4 tbsp). Stir in chili garlic sauce and sweetener, adjusting to taste.
Lay out your lettuce leaves. Spoon in the chicken mixture, drizzle with peanut sauce, and garnish with cilantro, green onions, or crushed peanuts.
Enjoy immediately as fresh lettuce wraps, or prep ahead and store chicken and sauce separately.