Whizz the ginger, chilies, white pepper and half of the coriander stalks, roots (if using) and leaves in a food processor until finely chopped. Mix the lactose free milk, garlic oil and gluten free breadcrumbs together in a large bowl. Add the spice mix and chicken into the breadcrumbs, then season.
Now, really mix – I mean mix – until the whole thing becomes a paste rather than lumpy. If you have a tabletop mixer, then use that instead of your hands. Shape into small balls. Place a large frying pan or casserole over a medium heat, add a drizzle of oil then fry the balls until well coloured – about 10 mins. You’ll need to do this in batches, adding more oil each time. Set aside.
For the broth, put the stock into a large saucepan, bring to the boil, then simmer. Add the sesame oil, fish sauce, ginger, remaining coriander stalks and roots, star anise and peppercorns. Simmer, covered, for 20 mins. Add the spring onions, rice noodles and chilies, if using. Take 6 large bowls, then divide the noodles between them – tongs are the best tool. Drop in the warm meatballs then ladle in the stock. Scatter with coriander and basil leaves then tuck in.