Creating the Korean Steak Sandwich is a simple process that results in a delicious meal. Follow these steps to ensure success:

1. Marinate the Steak: In a bowl, combine soy sauce, brown sugar, sesame oil, garlic, ginger, and red pepper flakes. Add the flank steak, ensuring it’s well coated. Cover and marinate for at least 20 minutes.

2. Preheat the Grill: Heat your grill or grill pan over medium-high heat. Ensure it’s hot before cooking the steak for optimal searing.

3. Cook the Steak: Remove the steak from the marinade and place it on the hot grill. Cook for about 4-5 minutes on each side or until it reaches your desired level of doneness. Let it rest for a few minutes before slicing.

4. Prepare the Sauce: In a small bowl, mix mayonnaise and gochujang until smooth. Adjust the amount of gochujang to suit your spice preference.

5. Toast the Bread: While the steak rests, lightly toast the slices of crusty bread on the grill or in a toaster.

6. Assemble the Sandwich: Spread the gochujang mayo on each slice of bread. Layer the sliced steak, kimchi, cucumber, and shredded carrots on one slice. Top with cilantro and cover with the other slice of bread.

7. Serve Immediately: Cut the sandwich in half and serve while warm, allowing the flavors to meld beautifully.

These steps will guide you in creating an incredible Korean Steak Sandwich that is sure to impress.