In a small bowl, whisk together the peanut butter, coconut aminos, rice vinegar, grated ginger, and minced garlic until the sauce is smooth and emulsified.
Heat the toasted sesame oil in a large skillet or wok over medium-high heat.
Add the ground chicken to the skillet, seasoning with sea salt and black pepper, and cook while breaking it apart with a spatula until browned and fully cooked.
Add the diced red bell peppers to the skillet and sauté for 2-3 minutes until they are slightly softened but still retain a bit of bite.
Pour the prepared peanut sauce over the chicken and pepper mixture, stirring constantly for 1 minute to ensure everything is glazed and heated through.
Remove the skillet from the heat and stir in half of the sliced green onions.
Wash and pat dry the butter lettuce leaves, then lay them flat on a serving plate.
Spoon the chicken mixture evenly into the center of each lettuce leaf.
Garnish with the remaining green onions before serving immediately.