Begin by slicing the ribeye or sirloin into thin strips. In a mixing bowl, whisk together soy sauce, gochujang, sesame oil, brown sugar, minced garlic, and black pepper until well combined. Add the beef to the marinade, ensuring each piece is fully coated. Cover and refrigerate for at least 30 minutes, or preferably overnight, to let the flavors deeply infuse.

While the beef marinates, create the creamy sauce. In a separate bowl, whisk together mayonnaise, sriracha, sesame oil, garlic powder, and a pinch of sugar until smooth and well blended. Cover and chill in the refrigerator.

In a large pot, bring 4 cups of water to a simmer over medium heat. Add gochugaru, soy sauce, rice vinegar, and salt, stirring to combine. Add the ramen noodles and cook according to package instructions, usually around 3 minutes until al dente. Stir occasionally to prevent sticking, then remove from heat.

Heat a skillet or grill pan over high heat until it’s smoking hot. Remove the marinated beef from the refrigerator and sear for 2-3 minutes on each side. Transfer to a plate to rest before slicing into bite-sized pieces.

To assemble your ramen, divide cooked noodles among bowls. Ladle the flavorful broth over the noodles, drizzle the creamy sauce on top, and arrange the sliced grilled beef. Garnish with chopped green onions and black sesame seeds.