In a large bowl, combine the ground beef with the rest of the meatball ingredients.
Mix the meat mixture until all ingredients are incorporated.
Shape into 1 1/2" balls, ending up with about 20 meatballs.
In a small bowl, combine the water chestnuts, green onions, garlic and ginger in a bow and mix well.
In a separate bowl, mix the hoisin sauce, garlic chili sauce and soy sauce.
Layer the meatballs, water chestnut mixture and sauce mixture alternately in a slow cooker until all of the ingredients are used.
Cook on High for 2 hours (Low for 4-6 hours) stirring occasionally to ensure even cooking.
Reduce the heat to low and serve when ready. Sprinkle with sliced green onions and sesame seeds if desired and use the pot juices as a dipping sauce.
Notes
To make this recipe even easier, you may use precooked, frozen meatballs. Cooking time will not be affected. If you use uncooked pre-made frozen meatballs, increase cooking time by 30 minutes.1/4 cup of garlic chili sauce will give you mild spiciness and will be good for most people. 1/2 a cup will result in moderate spiciness. Increase to 3/4 - 1 cup if you like really spicy food.