Preheat oven to 400°F (200°C). Slice the baguette lengthwise (or into sandwich-length sections) about 1/2–3/4-inch thick slices or open the loaf for a full baguette sandwich.

Make garlic butter: soften unsalted butter to room temperature, then mix thoroughly with minced garlic and chopped parsley. If desired, whisk in 1 tsp olive oil for a smoother spread and to help browning.

Spread and toast: evenly spread the garlic butter on cut sides of the baguette. Place on a baking sheet, buttered side up, and toast in the preheated oven 6–8 minutes until golden and crisp at edges. If you prefer a softer interior, toast 4–5 minutes.

Bulgogi (Korean marinated beef)

Make marinade: in a bowl combine soy sauce, brown sugar, mirin, sesame oil, rice vinegar, grated pear or apple (if using), minced garlic, minced ginger, sliced green onion, and black pepper. Stir to dissolve sugar.

Marinate beef: add the thinly sliced beef to the marinade and toss to coat thoroughly. Marinate at room temperature for 15–30 minutes or refrigerate 1–2 hours for deeper flavor (if refrigerating, bring to room temperature 20 minutes before cooking).

Cook bulgogi: heat 1 tsp vegetable oil in a large skillet or cast-iron pan over medium-high heat until shimmering. Add marinated beef in a single layer (work in batches if necessary) and cook 2–4 minutes, stirring or flipping, until beef is browned and slightly caramelized. Remove from heat and reserve. Scrape up any browned bits; they add flavor.

Adjust seasoning: taste a small piece and add a pinch more soy or sugar if needed. Keep warm until assembly.

Spicy mayo & toppings

Make spicy mayo: in a small bowl combine mayonnaise, gochujang, Sriracha (if using), and lime juice or rice vinegar. Stir until smooth and taste for spice/acid balance. Adjust to taste.

Prepare toppings: if using cucumber and red onion, slice thinly. For a quick pickle: toss 1 tbsp sliced cucumber and 1 tbsp red onion with 1/2 tsp rice vinegar and a pinch of sugar and salt; let sit 5–10 minutes. Crumble feta and chop garnish herbs or green onion.

Assemble baguette: spread a generous layer of spicy mayo on the bottom half of the toasted baguette. Pile warm bulgogi over the mayo in an even layer. Scatter quick-pickled cucumber and red onion (if using) over the beef. Sprinkle crumbled feta evenly, then add toasted sesame seeds and garnish with cilantro or sliced green onion.

Finish & serve: place top half of baguette in place, press gently, and slice into serving portions. Serve immediately while bulgogi is warm so the garlic buttered bread is crisp and the feta contrasts creamy-salty with the spicy-sweet beef.