If your beef isn't pre-sliced, use a very sharp knife to cut it against the grain into paper-thin strips (partially freezing beef for 30 minutes makes slicing easier). In a large bowl, whisk together soy sauce, brown sugar, sesame oil, grated pear/apple, minced garlic, grated ginger, black pepper, and half of the chopped green onions. Add the thinly sliced beef to the marinade, tossing well to ensure every piece is coated.

Cover the bowl with plastic wrap and refrigerate for at least 2 hours, or ideally overnight (8-12 hours) for maximum flavor. The longer marination time allows the flavors to penetrate the meat and the pear/apple enzymes to tenderize the beef, resulting in a more delicious and tender bulgogi.

Rinse the short-grain white rice under cold running water until the water runs clear. Combine the rinsed rice with 3 cups of water in a saucepan. Bring to a boil over high heat, then immediately reduce the heat to the lowest setting, cover tightly, and cook for 15 minutes. Do not lift the lid during cooking!

Heat a large non-stick skillet or cast-iron griddle over medium-high heat until hot. Add a small amount of oil if your pan isn't perfectly non-stick. Cook the marinated beef in a single layer, in batches if necessary, to avoid crowding the pan. Cook for 2-3 minutes per side until beautifully caramelized and cooked through. Crowding will steam the meat instead of searing it.

Transfer the cooked bulgogi to a serving platter. Fluff the rested rice gently with a fork and serve alongside the bulgogi. Garnish the bulgogi with the remaining fresh chopped green onions and a sprinkle of toasted sesame seeds. Serve immediately with fresh lettuce leaves (for wrapping) and kimchi on the side.