In a large bowl, combine ground pork, ground chicken, egg, panko breadcrumbs, 2 tablespoons soy sauce, 1 tablespoon sesame oil, minced garlic, grated ginger, and black pepper. Mix gently until just combined. Do not overmix.
Roll the mixture into 1-inch meatballs. You should have about 20-25 meatballs.
In a small bowl, whisk together hoisin sauce, 0.25 cup soy sauce, rice vinegar, 1 tablespoon sesame oil, and honey. In a separate small bowl, whisk together cornstarch and water to create a slurry.
Heat 1 tablespoon of oil in a large skillet over medium-high heat. Add meatballs in a single layer (cook in batches if necessary) and brown on all sides. This will take about 5-7 minutes.
Pour the sauce mixture into the skillet with the browned meatballs. Bring to a simmer.
Slowly whisk the cornstarch slurry into the simmering sauce. Continue to cook, stirring, until the sauce thickens, about 2-3 minutes.
Garnish with sesame seeds and sliced green onions, if desired. Serve hot.
Notes
These meatballs are fantastic served over rice, with noodles, or as part of a larger appetizer platter.