01 - Combine beef slices with soy sauce, sesame oil, Sriracha, garlic, and black pepper in a bowl. Let marinate for at least 15 minutes to develop flavors.
02 - In a large pot, combine chicken or beef broth, miso paste, soy sauce, mirin, chili oil, ginger, and green onion whites. Bring to a simmer over medium heat, cover, and let simmer gently for 20 minutes to infuse flavors.
03 - Melt butter in a saucepan over medium heat. Add minced garlic and sauté until fragrant, about 1-2 minutes. Lower heat, add heavy cream and cream cheese, stirring until smooth. Add soy sauce and season with salt and pepper. Simmer gently for 3-4 minutes, then remove from heat.
04 - Heat a large skillet or wok over high heat. Quickly sear the marinated beef for 2-3 minutes until just cooked through. Remove from heat and set aside.
05 - Cook ramen noodles according to package instructions. Drain and divide among serving bowls. Arrange soft-boiled eggs (halved), bean sprouts, spinach, and seared beef over the noodles.
06 - Ladle hot broth into each bowl. Drizzle creamy garlic sauce generously over the top. Garnish with green onions, sesame seeds, and sliced red chili if desired. Serve immediately while hot.