Peel the ginger and slice it into coins. Lightly crush the slices using the flat side of a knife or a meat mallet. Thinly slice the green onion tops to obtain 2–3 tablespoons for garnish. Cut the remaining portions into short lengths, bruise them, and combine with the ginger. Coarsely chop the leafy cilantro tops to yield 2 tablespoons, reserving them for garnish. Set aside the remaining cilantro sprigs.

In a 3–4 quart (3–4 L) pot, toast the coriander seeds and clove over medium heat for 1–2 minutes, or until fragrant. Add the ginger slices and green onion sections, stirring briefly until aromatic, approximately 30 seconds.

Remove the pot from the heat and allow it to cool slightly for 15 seconds. Pour in the chicken broth. Return the pot to the burner and add the water, cilantro sprigs, chicken, and salt. Bring to a boil over high heat, then reduce to a gentle simmer.

After 5–10 minutes of simmering, remove the chicken once it is firm and fully cooked. Transfer it to a bowl and rinse with cold water to halt further cooking. Drain and allow it to cool. Once cooled, shred or cut the chicken into bite-size pieces and cover lightly to prevent drying.

Allow the remaining broth to continue simmering for an additional 15–20 minutes, ensuring a total simmering time of approximately 30 minutes.

Soak the dried rice noodles in hot water until they become pliable and opaque. Drain, rinse, and set aside.

Once the broth has finished simmering, strain it through a fine-mesh strainer positioned over a 2-quart (2-L) pot. For a clearer broth, line the strainer with muslin. Discard the solids. You should obtain approximately 4 cups of broth. Season the broth with fish sauce and sugar or maple syrup, adjusting to achieve a balanced savory-sweet flavor.

Bring the strained broth to a boil. Place the softened rice noodles in a noodle strainer or mesh sieve and briefly immerse in the boiling broth for 5–60 seconds to heat and soften. Divide the noodles between two bowls. Reduce the heat to maintain the broth at a hot temperature while arranging the shredded chicken on top of the noodles. Garnish with the chopped green onion, cilantro, and pepper, if desired. Taste and adjust seasoning as needed. Return the broth to a boil and ladle it into the bowls. Serve immediately with optional garnishes.