In a large pot, combine the chicken thighs, minced garlic, sliced ginger, chopped scallion whites, kosher salt, ground pepper, and water. Bring to a boil over high heat, about 5-7 minutes.

Once boiling, reduce heat to medium-low and let simmer uncovered for 15 minutes until chicken is cooked through.

While chicken simmers, whisk together black rice vinegar, soy sauce, and toasted sesame oil. Adjust with crispy chili oil if desired.

Remove cooked chicken, shred into bite-sized pieces, and set aside.

Add noodles and matchstick carrots to the boiling broth. Cook according to package instructions, about 3-4 minutes.

After noodles are cooked, return shredded chicken to the pot and stir to combine, warming through for an additional minute.

Serve in bowls, garnishing with reserved scallion greens and drizzling the prepared sauce on top.