Freeze to slice: Place beef in the freezer for 20–30 minutes to firm up.
This makes thin slicing easier. Slice against the grain into very thin strips.
Make the marinade: In a bowl, whisk soy sauce, brown sugar, sesame oil, garlic, ginger, rice vinegar, and gochujang. Stir in the grated pear.
The pear helps tenderize the meat and adds natural sweetness.
Marinate the beef: Add sliced beef and onions to the marinade. Toss to coat. Let sit for 10–15 minutes while you prep rice and toppings.
For deeper flavor, marinate up to 4 hours in the fridge.
Heat the pan: Set a large skillet or cast-iron pan over medium-high heat. Add the neutral oil and let it shimmer. You want the pan hot for quick searing.
Cook in batches: Add a single layer of beef and onions, shaking off excess marinade.
Cook 2–3 minutes, stirring once or twice, until the edges caramelize. Flip or stir and cook 1–2 minutes more. Repeat with remaining beef, adding a touch more oil if needed.
Finish and garnish: Return all beef to the pan.
Toss with green onions and sesame seeds. Taste and adjust with a splash of soy sauce or a pinch of sugar if needed.
Serve: Spoon over hot rice or tuck into crisp lettuce leaves. Add kimchi, cucumber, or a fried egg if you like.