In a small bowl, whisk together soy sauce, brown sugar, rice vinegar, mirin, sesame oil, and red pepper flakes until well combined. Set aside for later use.

Warm neutral oil in a large skillet over medium heat until shimmering.

Add ground beef to the hot skillet, breaking it apart with a spatula. Cook for about 5-7 minutes, stirring occasionally, until browned and fully cooked.

Stir in minced garlic, grated ginger, and diced yellow onion; sauté until onions are translucent.

Pour the prepared sauce into the skillet with the beef. Stir and allow to cook for an additional 2-3 minutes until the sauce thickens.

Taste the mixture and adjust with salt if needed.

Spoon the beef mixture over cooked rice and garnish with sesame seeds and cooked vegetables.