In the subject-verb agreement, the subject and the verb should agree with each other in number that is singular or plural. Therefore, the subject is plural then the verb form is plural and if the subject is singular then the verb form is singular.
Therefore, pair of verb which correctly completes the sentence is 'was, was' written as,
At the dig, bread and butter was served, and every man and woman was hungry.
Since in the sentence above, bread and butter are two objects and plural, but the butter and bread being in singular form, verb agree with the subject and hence is written in singular form 'was.'