Step 1: Dismiss everyone
As we can see Frankie & Benny's procedure is significantly different from the the correct procedure which is laid down in law and as such Frankie & Benny's have acted unlawfully in their dismissal of the staff.
As a staff member you have rights. These rights that cannot simply be thrown away on the whim of an employer. You do need put in a claim to protect yourself as the administrators will not prioritise your claim unless you have representation.