In a large skillet, heat the vegetable oil over medium heat. Add the chopped onion and sauté for 2-3 minutes until translucent.

Add the minced garlic and cook for an additional 30 seconds until fragrant.

Stir in the ground chicken or turkey, breaking it apart with a spoon. Cook until browned and cooked through, about 5-7 minutes.

Add the chopped mushrooms, red bell pepper, and grated carrot to the skillet. Cook for another 3-4 minutes until the vegetables are tender.

In a small bowl, mix together the soy sauce, hoisin sauce, rice vinegar, sesame oil, and black pepper. Pour this sauce over the cooked chicken and vegetables, stirring to combine. Cook for an additional 2 minutes to heat through.

Remove from heat and let the mixture cool slightly.

To serve, spoon the chicken mixture into the center of a lettuce leaf, fold it like a taco, and garnish with chopped green onions and sesame seeds.