1. Wash and dry chicken
2. Turn bird breast side down. Using kitchen shears cut along the backbone. Cut along the other side of the backbone and remove (can be used for making chicken stock later).
3. Turn bird breast side up and press hard on breast bone with both hands to flatten chicken.
4. Remove wing tips if desired. Tuck legs and wings close to body.
5. Follow favourite oven or BBQ recipe.
*late 18th century (originally an Irish usage): perhaps related to the noun dispatch + cock
"Ideas won't keep; something must be done about them."