01 - Combine the sliced beef with soy sauce, mirin, sesame oil, and cornstarch in a bowl. Let marinate for at least 15 minutes while preparing other components.
02 - Bring a pot of water to a gentle boil. Carefully lower in the eggs and simmer for exactly 6½ minutes. Immediately transfer to an ice bath to stop cooking, then peel and set aside.
03 - Heat vegetable oil in a large saucepan over medium heat. Add garlic and ginger; sauté for 1 minute until fragrant. Stir in chili paste and miso, cooking for another minute to bloom flavors.
04 - Pour in stock, soy sauce, rice vinegar, and brown sugar. Bring to a simmer and cook for 10 minutes to develop depth.
05 - Prepare ramen noodles according to package instructions. Drain well and set aside, tossing with a small amount of oil to prevent sticking if needed.
06 - Heat a separate pan over high heat. Quickly sear the marinated beef for 2–3 minutes until just cooked through. Remove from heat immediately to maintain tenderness.
07 - Add mushrooms and carrots to the simmering broth; cook for 3 minutes until just tender-crisp.
08 - Divide noodles between four bowls. Ladle over the hot broth with vegetables. Arrange beef slices, halved soft-boiled eggs, spinach, spring onions, chili slices, sesame seeds, and nori on top.
09 - Serve while piping hot for optimal texture and flavor.