Peel and slice the garlic and ginger. Place in a large saucepan with the chicken breasts (keep them whole) and hot water.
Cover and bring to a simmer for 10-15 minutes, depending on their size. The chicken is cooked when it is white all the way through. Remove the chicken from the saucepan, (keep the cooking water), and place on a chopping board to cool slightly.
Add half (200g) of the sweetcorn and the stock cube to the saucepan. Blend thoroughly with a stick blender, or food processor. Return to the pan and bring back to the boil.
Shred the chicken with 2 forks, return to the saucepan and add in the rice wine and remaining 200g of sweetcorn. Heat until the soup has bubbled through for 2-3 minutes.