This is a hard question to answer. You see, in the past texts on what people ate in more detail than "bread, cheese, pottage, etc" was difficult to come by. In Roman classical period if becomes even more difficult. Cookbooks (or what could vaguely be called one by modern standards) were written entirely by the wealthy upperclassmen who would rather put interesting or complex dishes in their works than a simple sops (bread with liquid).

The closest to your answer I can give (according to late antiquity) is from the Gospel of John. 13:21-26.

When Jesus had thus said, he was troubled in spirit, and testified, and said, Verily, verily, I say unto you, that one of you shall betray me. Then the disciples looked one on another, doubting of whom he spake. Now there was leaning on Jesus' bosom one of his disciples, whom Jesus loved. Simon Peter therefore beckoned to him, that he should ask who it should be of whom he spake. He then lying on Jesus' breast saith unto him, Lord, who is it? Jesus answered, He it is, to whom I shall give a sop, when I have dipped it. And when he had dipped the sop, he gave it to Judas Iscariot, the son of Simon.

Sop could reference anything from bread and vinegar to bread and fine wine, so it is a bit vague. However, what this does tell us, since the Gospel of John was written 90-100 AD in the eastern Mediterranean (a well populated roman province) we can extrapolate that sops were a well understood (maybe even ubiquitous) foodstuff in the area and thus of much of Rome, especially with how simple it is.

Sorry if this doesn't tell you much, but the time was so long ago and culinary writings were in their infancy.