Prep the aromatics and chicken. Mince the garlic and grate the ginger. Slice the green onions, keeping whites and greens separate. Pat the chicken dry, season with salt and pepper, and toss with the cornstarch to lightly coat.

Toast the sesame seeds. In a dry pot or Dutch oven over medium heat, add sesame seeds and toast until golden and fragrant, about 1–2 minutes. Transfer to a small bowl for later.

Sear the chicken. Heat the neutral oil in the same pot over medium-high. Add chicken in a single layer and cook until browned and just cooked through, 4–6 minutes. Work in batches to avoid steaming. Remove to a plate and keep warm.

Sweat the aromatics. Reduce heat to medium. Add a drizzle of oil if the pot looks dry. Add green onion whites, garlic, and ginger. Cook 30–60 seconds, stirring, until fragrant. Do not let the garlic burn.

Build the broth. Pour in chicken broth, soy sauce, brown sugar or honey, and chili-garlic sauce if using. Stir and bring to a gentle simmer. Let it bubble for 5–7 minutes to marry the flavors.

Add veggies. Drop in mushrooms and carrots first if using, and simmer 3–4 minutes. Add quick-cooking greens like spinach or bok choy in the last 1–2 minutes so they stay bright.

Cook the noodles. For best texture, cook ramen in a separate pot of boiling water according to package directions minus 30–60 seconds. Drain well. This keeps the broth clear and the noodles springy.

Finish the soup. Return the chicken (and any juices) to the pot. Stir in toasted sesame oil, rice vinegar, and half the toasted sesame seeds. Taste and adjust seasoning with soy sauce, salt, or a pinch more vinegar.

Assemble. Divide noodles between bowls. Ladle hot broth and chicken over top. Garnish with green onion greens, remaining sesame seeds, and any optional toppings like soft-boiled egg or chili oil.

Serve immediately. Ramen is best hot and freshly assembled so the noodles keep their bite.