Finely chop the carrot, cabbage, french beans, ginger, and garlic, and cut the chicken into small pieces, keeping the spring onion whites and greens separate.

Add the chicken pieces to the water in a saucepan and bring to a boil, skimming off any foam that rises to the surface, until the chicken is fully cooked through.

Remove the cooked chicken pieces from the stock, let them cool slightly, then shred the meat into thin strands and discard the bones.

Heat the oil in a separate pan and sauté the ginger, garlic, and spring onion whites until fragrant and just softened.

Add the carrot, cabbage, and french beans to the sautéed aromatics, then pour in the reserved chicken stock.

Bring the soup to a gentle simmer and cook until the vegetables are tender but still have a slight bite.

Return the shredded chicken to the pan and stir it into the simmering soup so it warms through evenly.

Stir in the crushed black peppercorns, soy sauce, vinegar, and salt, tasting and adjusting the balance of pepper and tang.

Turn off the heat, let the soup rest briefly, then ladle into bowls and garnish with the reserved spring onion greens.