In a mixing bowl, combine soy sauce, brown sugar, minced garlic, grated ginger, and sesame oil. Stir until the sugar is dissolved and the marinade is well blended. Add the ground beef, ensuring it’s thoroughly coated. Cover and refrigerate for at least 1 hour.

Remove the beef from the refrigerator. Divide the beef into equal portions and form each portion into burger patties, roughly ¾ inch thick. Make a small indentation in the center of each patty.

Preheat your grill to medium-high heat. Place the burger patties on the grill and grill for approximately 4-5 minutes on each side for medium doneness.

Slice the burger buns in half and lightly brush the cut sides with sesame oil or butter. Toast them on the grill or a skillet for about 2-3 minutes.

Assemble by placing a grilled patty on the bottom bun, adding kimchi, fresh lettuce, tomato slices, and cheese if desired. Finish with the top bun.

Serve immediately while hot and enjoy with sides like sweet potato fries.