Mom's Asian Chicken Lettuce Cups

1. Mix together the chicken broth, cornstarch, soy sauce, and Chinese oyster sauce for the stir-fry sauce and set aside; preheat oven to 300F.
2. Spread the chow mein noodles in one layer on a small baking sheet; mix together the melted butter and Worcestershire sauce and pour it on the chow mein; toss to coat evenly and bake for 10-15 minutes until golden brown and crispy.
3. Preheat a wok or pan over medium-high heat and add the avocado oil, minced ginger, minced garlic, and chopped shiitake mushrooms; stir fry with a sprinkle of salt and pepper for 2-3 minutes.
4. Add the ground chicken along with another sprinkle of salt and pepper and stir fry until cooked through (3-4 minutes), breaking the chicken up with your spatula.
5. Add the water chestnuts and the prepared stir-fry sauce (mix the sauce first because the cornstarch will settle) and cook until the sauce thickens and clings to the chicken mixture (1-2 minutes).
6. Mix in the sliced scallions and rice vinegar, cook for 1 more minute, and turn off the heat.
7. Serve with butter lettuce leaves and crispy chow mein noodles and enjoy!