In a bowl, whisk together soy sauce, gochujang, sesame oil, brown sugar, minced garlic, and black pepper. Coat the ribeye or sirloin steak in the marinade, cover, and refrigerate for at least 30 minutes.

Preheat the grill or stovetop pan to medium-high heat. Once hot, add the marinated steak and cook for 3-4 minutes on each side for medium-rare. Transfer to a cutting board and let it rest for 5 minutes, then slice it thinly against the grain.

Bring a pot of water to a boil and add the instant ramen noodles. Cook for 2-3 minutes until just tender, then drain and rinse briefly under cold water. Set aside.

In a large pot, heat your choice of broth over medium heat until simmering. Stir in gochugaru, soy sauce, rice vinegar, sesame oil, and a pinch of salt. Simmer for about 2 minutes.

In a small bowl, mix together mayonnaise, sriracha, sesame oil, garlic powder, and brown sugar until smooth. Adjust sriracha for desired spice level.

To serve, divide the cooked noodles between bowls, ladle hot broth over the noodles, arrange sliced beef on top, drizzle with the creamy sauce, and garnish with green onions and toasted sesame seeds.