In a large bowl, gently mix the ground beef, Panko breadcrumbs, egg, 1 tablespoon of soy sauce, 1 minced garlic clove, and 1 teaspoon of minced ginger. Do not overmix. Form into 1-inch meatballs.

Stovetop: Heat 1 tablespoon of vegetable oil in a large skillet over medium-high heat. Brown meatballs on all sides, about 5-7 minutes. Remove and set aside. Oven: Preheat oven to 400°F (200°C). Place meatballs on a parchment-lined baking sheet and bake for 15-20 minutes until cooked through.

In the same skillet (grease drained), sauté the remaining 2 cloves of minced garlic and 2 teaspoons of ginger over medium heat for 30 seconds until fragrant.

Stir in the 1/2 cup soy sauce, 1/2 cup water, and brown sugar. Bring to a simmer, stirring until the sugar dissolves.

In a small bowl, whisk the cornstarch and 2 tablespoons of cold water to make a slurry. Slowly pour the slurry into the simmering sauce, whisking constantly until it thickens. Return the cooked meatballs to the skillet and toss to coat. Simmer for 2-3 minutes.

Serve immediately over rice or noodles, garnished with sliced green onions or sesame seeds if desired.