In a large skillet over medium-high heat, add the ground beef and cook, breaking it apart with a spatula, until browned and cooked through, about 6-8 minutes.
Drain excess fat from the skillet if necessary.
Reduce heat to medium and add the minced garlic and grated ginger to the beef. Cook for 1 minute until fragrant.
Add the soy sauce, brown sugar, sesame oil, crushed red pepper flakes, and black pepper to the skillet. Stir well to combine all ingredients.
Simmer the beef mixture for 3-5 minutes, stirring occasionally, until the sauce thickens slightly.
Remove the skillet from heat and stir in half of the sliced green onions.
Divide the cooked rice evenly among four meal prep containers or freezer-safe containers.
Top each rice portion with the Korean beef mixture.
Sprinkle the remaining green onions and toasted sesame seeds on top of each bowl.
Allow the bowls to cool completely before sealing and freezing.
To reheat, thaw overnight in the refrigerator and microwave until heated through, about 2-3 minutes.