Step 1

Arrange a rack in the middle of the oven and heat the oven to 375°F. Line a rimmed baking sheet with parchment paper.

Step 2

Finely chop 1/2 medium yellow onion and 2 garlic cloves. Place both in a large bowl. Add 1 pound ground beef, 1/2 cup panko breadcrumbs, 1 large egg, 2 tablespoons sweet chili sauce, 1 tablespoon oyster sauce, 1 tablespoon soy sauce, 1 teaspoon toasted sesame oil, 1 teaspoon ground ginger, and 1/4 teaspoon black pepper. Mix together with your hands until evenly combined.

Step 3

Using wet hands or a cookie scoop, portion the mixture into about 26 meatballs (about 1 1/2 tablespoons each). Roll each one between your hands to form a smooth ball. Place on the baking sheet, spacing them evenly apart.

Step 4

Bake for 15 minutes. Meanwhile, make the glaze: Place 3 tablespoons sweet chili sauce, 1 tablespoon ketchup, 1 tablespoon rice vinegar, 1 tablespoon oyster sauce, 1 tablespoon soy sauce, 1 tablespoon honey, and 1 teaspoon toasted sesame oil in a small saucepan. Bring to a simmer over medium-low heat, stirring occasionally. SImmer until slightly thickened and syrupy, 3 to 5 minutes. Remove the saucepan from the heat.

Step 5

Remove the meatballs from the oven and brush the meatballs with the glaze, using it all.

Step 6

Return the meatballs to the oven. Bake until cooked through, 5 to 7 minutes more. Sprinkle with 1 tablespoon toasted sesame seeds.