Slice the beef thin. For clean, thin slices, chill the steak in the freezer for 20–30 minutes first. Slice across the grain into 1/8-inch pieces. Thin slices cook quickly and get the signature crispy edges.

Make the marinade. In a bowl, whisk soy sauce, brown sugar, grated pear, garlic, ginger, sesame oil, rice vinegar, and neutral oil. Add gochugaru or a little gochujang if you want gentle heat.

Marinate. Toss the beef with the marinade and half the green onions. Cover and chill for at least 30 minutes and up to 24 hours. The longer it sits, the deeper the flavor—but even 30 minutes works well.

Prep the air fryer. Preheat to 400°F (200°C) for 3–5 minutes. Lightly oil the basket or line it with a perforated parchment sheet to reduce sticking and smoke.

Drain and arrange. Lift the beef from the marinade, letting excess drip off. Lay pieces in a single layer with minimal overlap. If using onions, carrots, or mushrooms, toss a small handful in as well, but don’t overcrowd. Cook in batches if needed.

Air fry. Cook at 400°F (200°C) for 5–7 minutes, shaking halfway. For caramelized edges, cook an extra 1–2 minutes. Thinner cuts will cook faster; keep an eye on the first batch to nail your timing.

Finish and garnish. Transfer to a plate and sprinkle with sesame seeds and the remaining green onions. Repeat with the remaining beef.

Serve. Enjoy over hot rice, tucked into lettuce leaves with kimchi, or in a bowl with cucumbers and a fried egg. A drizzle of extra sesame oil or a swipe of gochujang is great if you like more richness or heat.