Roll the spatchcock and tie with string.
Combine the stock ingredients and 1 cup of water in a saucepan just big enough to for the spatchcock, bring to the boil then simmer gently for 10 minutes.
Add the rolled spatchcock to the saucepan and cover with a piece of baking paper. Simmer for 15 minutes.
Remove the spatchcock from the poaching liquid and pat dry with a paper towel.
Heat the oil in a frypan and fry the spatchcock until crisp. Meanwhile reduce the stock slightly and pass through a sieve.
Remove the string from the spatchcock and serve with the spring onion and drizzled with cooking liquid.