In a bowl whisk together mayonnaise, sriracha, grated ginger and vinegar. Stir in the broccoli slaw. Mix well. Cover and refrigerate for 30 minutes.
Preheat oven to 350 degrees.
In a bowl combine ground pork, egg, breadcrumbs, oyster sauce, sesame oil, soy sauce, ginger, salt and serrano peppers. Mix well and roll into about 20 meatballs.
Heat peanut oil in a skillet over medium heat. Brown on all sides, transfer to a baking dish and in preheated oven for 20 minutes or until cooked through.
When ready to assemble sandwiches, place a couple sprigs of cilantro, 1 lettuce leaf and 5 meatballs per sandwich on the hoagie rolls, top with sriracha slaw and serve.