01 - Combine beef slices with soy sauce, sesame oil, Sriracha, garlic, and black pepper in a bowl. Let marinate for at least 15 minutes before cooking.
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 simmer gently for 20 minutes.
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, season with salt and pepper, and simmer gently for 3-4 minutes before removing 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 - Boil ramen noodles according to package instructions, drain, and divide among serving bowls. Arrange halved soft-boiled eggs, 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.