1.5 pounds ribeye steak – thinly sliced across the grain
1 each onion – thinly sliced
1 tbsp neutral oil
sesame seeds – toasted (for serving)
Instructions
If your meat is not pre-sliced, freeze it for 30 minutes to firm up, then slice across the grain about 1/8 inch thick.
In a large bowl, whisk the soy sauce and light brown sugar until the sugar dissolves. Grate the Korean pear directly into the bowl, then add the garlic, scallions, sesame oil, and black pepper; stir to combine.
Add the ribeye steak and the thinly sliced onion to the bowl, tossing well to coat and separating the slices. Cover and refrigerate for 30 minutes to 2 hours.
Heat a large heavy skillet or grill pan over high heat until very hot; add the neutral oil.
Working in 2–3 batches to avoid crowding, add a single layer of the marinated beef-and-onion mixture. Cook undisturbed until well browned at the edges, 2–3 minutes, then flip and stir until just cooked through and glossy, 1–2 minutes more. Transfer to a platter and repeat with remaining mixture.
Sprinkle with toasted sesame seeds and serve immediately.