Thinly slice the flank steak against the grain and season it with salt, black pepper, and half of the sesame oil. Allow it to marinate for about 10 minutes.

Heat a grill pan over medium-high heat and add vegetable oil. Cook the marinated steak for approximately 2 minutes on each side until medium doneness.

In the same pan, add the remaining sesame oil and lower the heat. Sauté the minced garlic and grated ginger for about 1 minute until fragrant.

Add gochujang, gochugaru, soy sauce, and sugar to the pan. Stir to combine and let it cook for another minute before pouring in the chicken stock.

Mix cornstarch with cold water in a small bowl to create a slurry and whisk it into the simmering broth until it thickens slightly.

Lower the heat and stir in the heavy cream, adjusting the seasoning with additional salt and pepper as needed.

Cook the fresh ramen noodles according to package instructions, then drain and divide them into serving bowls.

Ladle the creamy broth over the cooked noodles and top with grilled beef slices, garnishing with green onion, sesame seeds, and cilantro.