Bring a saucepan of water to a boil. Lower in the eggs and cook for 6 1/2 to 7 minutes for jammy centers, or 9 to 10 minutes for fully set yolks. Transfer the eggs immediately to an ice bath, peel them, and halve just before serving.

Heat the neutral oil in a large pot over medium heat. Add the garlic and ginger and cook for about 30 seconds, just until fragrant. Add the chicken broth, soy sauce, miso, toasted sesame oil, rice vinegar, and brown sugar, then whisk until the miso dissolves.

Bring the broth to a gentle simmer and cook for 8 to 10 minutes. If using mushrooms, add them during the last 3 to 4 minutes so they soften while retaining a pleasant bite.

Add the ramen noodles to the simmering broth and cook according to the package directions, usually 2 to 4 minutes. Fresh noodles generally cook faster than dried noodles, so check them early.

Stir in the bok choy or spinach and the shredded chicken. Cook for 1 to 2 minutes, until the greens wilt and the chicken is hot. Taste and adjust with additional soy sauce, rice vinegar, or chili oil.

Divide the noodles, chicken, vegetables, and broth among four bowls. Top each bowl with half an egg, sliced green onions, sesame seeds, nori, and chili crisp as desired.