In a large pot, combine boneless skinless chicken thighs, sliced garlic, finely chopped ginger, and the white parts of scallions. Season with kosher salt and pepper, and add 10 cups of water. Bring to a rolling boil.

Reduce heat to medium-low and let broth simmer uncovered for about 15 minutes, stirring occasionally until the chicken is tender.

While chicken simmers, whisk together the sauce ingredients in a separate bowl.

Remove chicken from the pot, shred into bite-sized pieces, and return to the pot along with the carrots.

Add dried ramen noodles to the pot and cook according to package instructions until tender.

Taste the broth, adjust seasoning if needed, ladle soup into bowls, and drizzle the sauce over each serving.