There are a few ways that can be used, but probably the most popular — and the one I tend to use — requires the patient to
lie lengthways along a cylindrical object such as a foam roller (or half roller).
Not exact matches
lace the chicken on a cutting board and split it
lengthways at the breastbone (but not in two halves) so that it will
lie flat.
Place the chicken on a cutting board and split it
lengthways at the breastbone (but not in two halves) so that it will
lie flat.