Heat oil in a deep saucepan over medium heat. Add garlic, ginger, and spring onion whites. Sauté gently until fragrant, making sure they do not brown. This forms the aromatic base of the soup.

Add chopped or shredded chicken to the pan. Stir well and cook until the chicken turns opaque and is lightly cooked through. This step ensures the chicken stays tender in the soup.

Add crushed sweet corn and pour in water or chicken stock. Stir well and bring the soup to a gentle simmer. Let it cook for a few minutes so the corn sweetness blends into the broth.

Lower the heat and slowly add the cornflour slurry while stirring continuously. Allow the soup to thicken slightly. The texture should remain light and silky, not overly thick.

Add soy sauce, black pepper, and salt as needed. Taste and adjust seasoning carefully. Simmer for another minute, then turn off the heat.

Let the soup rest briefly before serving. Ladle into bowls and garnish with chopped spring onion greens if desired.