01 - Whisk together soy sauce, brown sugar, sesame oil, garlic, grated pear, ginger, rice vinegar, and black pepper in a mixing bowl. Add sliced ribeye steak, ensuring even coating. Marinate for 15 to 30 minutes at room temperature.
02 - Heat a large skillet over medium-high heat. Add marinated beef slices, spreading evenly to prevent overcrowding. Cook for 3 to 4 minutes, stirring occasionally, until meat is browned and cooked through. Transfer beef to a plate and set aside.
03 - Return skillet to heat. Add a small amount of oil if necessary. Sauté sliced onions and bell peppers for 2 to 3 minutes until softened and slightly caramelized. Add chopped kimchi and continue stir-frying for 2 minutes until heated through and fragrant.
04 - Return cooked beef to the skillet. Toss beef with vegetables and kimchi mixture, stirring constantly for 1 to 2 minutes until all components are heated through and well combined. Remove from heat.
05 - Preheat broiler. Slice hoagie rolls in half lengthwise. Place rolls cut side up on a baking sheet. Toast under broiler for 1 to 2 minutes until lightly golden and crispy, watching carefully to prevent burning.
06 - Spoon bulgogi-kimchi mixture evenly onto the bottom halves of toasted rolls. Top each sandwich with 2 slices of provolone cheese. Place under broiler for 1 to 2 minutes until cheese is completely melted and bubbly.
07 - Sprinkle sliced scallions and toasted sesame seeds over melted cheese. Add a dollop of gochujang or mayonnaise if desired. Close sandwiches with top halves and serve immediately while hot.