In a large bowl, whisk together soy sauce, sesame oil, gochujang, brown sugar, grated Asian pear, minced garlic, fresh ginger, and rice wine vinegar until fully combined and smooth.

Add the thinly sliced beef to the marinade and toss to coat every piece thoroughly. Cover and refrigerate for at least 30 minutes, or up to 24 hours for maximum flavor. If you're short on time, even 15 minutes will make a difference.

In a medium bowl, whisk together rice wine vinegar, sugar, and salt until the sugar and salt dissolve completely.

Add julienned cucumbers and carrots to the pickling brine and toss to coat. Let sit at room temperature for at least 20 minutes, tossing occasionally. For best results, refrigerate for 1-2 hours or overnight. Drain before serving.

Combine gochujang, soy sauce, sesame oil, honey, rice wine vinegar, and minced garlic in a small bowl. Whisk until smooth and glossy. Taste and adjust — add more honey for sweetness, more gochujang for heat, or a splash more vinegar for brightness. Set aside.

Heat a large cast iron skillet or heavy-bottomed pan over high heat until smoking hot. Add the neutral oil and swirl to coat.

Working in batches to avoid crowding, add the marinated beef in a single layer. Do not move the meat for the first 60 seconds — let it sear and develop a deep caramelized crust. Toss and cook for another 30-60 seconds until the beef is cooked through and edges are charred. Remove to a plate and repeat with remaining beef.

Arrange chilled butter lettuce leaves across the bottom of each bowl or on a large platter, cup-side up.

Divide the seared beef among the lettuce cups. Top with drained pickled vegetables, shredded purple cabbage, sliced scallions, and toasted sesame seeds.

Drizzle generously with gochujang dipping sauce. Garnish with fresh cilantro and sliced jalapeño if desired. Serve immediately with extra dipping sauce on the side.