How to Make It
Preheat oven to 400°F. Combine beef, breadcrumbs, egg, garlic, and 1/4 teaspoon salt in a large bowl; shape into 20 meatballs. Arrange meatballs on a rimmed baking sheet lined with parchment paper. Bake at 400°F until cooked through, 15 to 20 minutes.
Meanwhile, bring a saucepan of water to a boil over medium-high. Add noodles; cook until al dente, 4 to 6 minutes for soba. Drain and rinse with cold water; drain. Place noodles in a large bowl. Toss with 2 teaspoons oil, 1 1/2 teaspoons vinegar, and remaining 3/8 teaspoon salt. Add cabbage, scallions, and carrots; toss to combine.
Stir together soy sauce, honey, Sriracha, remaining 1 teaspoon oil, and remaining 1 1/2 teaspoons vinegar in a medium skillet. Cook over medium, stirring occasionally, until slightly thickened. Add meatballs; toss to coat. Serve with noodles.