Heat the vegetable oil in a large skillet over medium-high heat.
Add the ground beef to the skillet and cook, breaking it apart with a spatula, until browned and cooked through, about 5-7 minutes.
Drain excess fat from the skillet if necessary.
Add the minced garlic and grated ginger to the beef and cook for 1 minute until fragrant.
In a small bowl, whisk together the soy sauce, brown sugar, sesame oil, and crushed red pepper flakes.
Pour the sauce mixture over the beef in the skillet and stir to combine.
Reduce the heat to medium and cook for an additional 3-5 minutes, allowing the sauce to thicken slightly.
Remove the skillet from heat and stir in the sliced green onions.
Sprinkle toasted sesame seeds over the top before serving.