01 - Whisk together soy sauce, brown sugar, sesame oil, garlic, pear, ginger, rice vinegar, and black pepper in a mixing bowl. Add sliced ribeye steak, ensuring even coating. Marinate for 15–30 minutes at room temperature.
02 - Heat a large skillet over medium-high heat until hot. Add marinated beef in a single layer, cooking for 3–4 minutes while stirring occasionally until browned and cooked through. Transfer beef to a plate and reserve.
03 - In the same skillet, add oil if needed. Sauté sliced onions and bell peppers for 2–3 minutes until softened. Add chopped kimchi and continue stir-frying for 2 minutes until fragrant and heated through.
04 - Return cooked beef to the skillet. Toss everything together, stirring for 1–2 minutes until the mixture is evenly combined and thoroughly heated.
05 - Preheat your broiler. Split hoagie rolls open and arrange cut side up on a baking sheet. Toast under the broiler for 1–2 minutes until lightly golden and crisp.
06 - Distribute the bulgogi-kimchi mixture evenly among toasted rolls. Top each sandwich with 2 slices provolone cheese. Return to the broiler for 1–2 minutes until cheese is melted and bubbly.
07 - Sprinkle with sliced scallions and toasted sesame seeds. Add gochujang or mayonnaise as desired. Serve immediately while hot and cheesy.