Preheat the oven to 450°F and lightly spray a mini muffin pan with cooking spray.
In a large bowl, combine panko and milk; let the milk absorb into the crumbs.
Add the ground chicken, minced garlic (meatballs), minced shallot, minced ginger (meatballs), beaten egg, 2 tsp soy sauce, kosher salt, and black pepper to the bowl; mix gently with your hands until just combined.
Using a medium scoop (about 2 tablespoons) or a tablespoon, portion the mixture into roughly 20–22 meatballs, roll slightly to shape, and place each into the wells of the prepared mini muffin pan.
Bake the meatballs for about 15 minutes, or until fully cooked through.
While the meatballs bake, heat vegetable oil and sesame oil in a medium saucepan over medium to medium-low heat.
Add the minced garlic (sauce) and minced ginger (sauce) and sauté 2–3 minutes, stirring regularly, until softened but not browned.
Stir in the oyster sauce, 3 tbsp soy sauce (sauce), and honey; simmer about 10 minutes, stirring occasionally, until slightly reduced.
Whisk the cornstarch and 1 tbsp water in a small bowl to make a slurry. Increase the heat slightly until the sauce lightly bubbles, then whisk in the slurry and cook 3–5 minutes until the sauce is thickened. Remove from heat.
Transfer the baked meatballs to a large bowl, drizzle the hot sweet oyster sauce over them, and gently fold to coat evenly.
To serve, place one to two meatballs in each lettuce leaf and top with optional garnishes (toasted sesame seeds, red bell pepper, cilantro, green onion). Serve with lime wedges.
