Preheat oven to 400 degrees F (200 degrees C) and grease a baking sheet.

Combine ground beef, panko, egg, 1 tablespoon soy sauce, 2 cloves garlic, and 1 teaspoon ginger in a bowl. Shape the mixture into 1 1/2-inch balls and arrange on the prepared baking sheet.

Bake meatballs for 10-12 minutes or until an instant-read thermometer registers 160 degrees F (71 degrees C).

Prepare the sauce by stirring together hoisin sauce, honey, vinegar, sesame oil, green onion, remaining soy sauce, remaining garlic, and 1/2 teaspoon ginger in a saucepan. Cook over medium-low heat until slightly reduced, approximately 5 minutes.

Reserve 2 tablespoons of sauce for green beans and coat the meatballs in the remaining sauce for 2 minutes.

Heat vegetable oil in a skillet over medium-high heat, cook green beans until tender and blistered, about 4-5 minutes. Add the reserved sauce and stir to coat.