Add the garlic, fresh ginger and the white half of the spring onions to a pestle and mortar and grind until you have a paste. Alternatively, grate or finely chop.
Add a little sesame oil to a pan over a medium heat and add the garlic, ginger, spring onion paste. Let that fry for around 3 minutes until fragrant then add in the coconut milk and water.
Stir and bring that to a gentle simmer then turn the heat to low and add in the chicken breast. Let that simmer and poach for around 5 minutes, making sure the soup doesn’t boil at any point as this will make the chicken tough.
If using fresh noodles, boil them in a separate pan for 3 minutes then drain and rinse under cold water to remove the starch. If using dry noodles, you can add them straight to the soup or boil them separately and cook until done.
Once both the chicken and noodles are cooked season the soup with a dash of fish sauce, the juice of ½ a lime and salt, to taste.
Place the noodles in a bowl and spoon the hot broth over. Top with chopped fresh coriander, the green end of the spring onion, finely sliced, and a final drizzle of sesame oil.
