Browning the ground beef: In a large skillet over medium heat, add your ground beef and let it brown until fully cooked. Make sure to break it apart as it cooks. Once done, drain any excess fat from the pan.
Adding aromatics: Toss the finely diced onion and minced garlic into the skillet with the browned beef. Stir occasionally for 2-3 minutes until the onion becomes fragrant and soft.
Flavor infusion: Drizzle in the soy sauce, sesame oil, rice vinegar, ground ginger, and red pepper flakes. Season generously with salt and black pepper. Stir together and cook for an additional 2-3 minutes.
Final touches: To serve, top with sliced green onions and a sprinkle of toasted sesame seeds.
Notes
For a spicier dish, adjust the red pepper flakes. Store leftovers in an airtight container in the fridge for up to 3 days.