We make our bread for the table meeting.
However, that would not have been what the Israelites ate while fleeing Egypt in the original Passover,
The Institution of the Eucharist was not a Passover meal. It was what the Passover meals were looking forward to. There is a distinction there. It is the reality, not the type or foreshadowing. The Last Supper is a not a participation in the Passover meal (seder), it is a participation in the Passion. Christ most certainly did not celebrate what we know as a the Jewish seder because the seder
looks forward to the coming of the Messiah and Christ
is the Messiah. That is also why it is gravely sinful to participate in Jewish seders or so-called "Christian seders".
Everything in Creation comes together in Christ. There were two sacrifices in the Jewish Temple -- the bloody and the unbloody, the sacrifice of animals and the sacrifice of bread and wine. Christ fulfills them both in His Passion. The bloody offering He made once, the unbloody offering He made at the Last Supper and renews daily on our altars around the world but they constitute a single sacrifice. The
form of the Eucharist -- the words used -- comes from the Last Supper but the
focus is not the "meal" aspect but on Christ's sacrifice of the Cross. We eat of the sacrifice of the altar in order to participate in it, but the eating is not the primary focus. It is Communion
with Christ, it is only adjunctly communion with
our neighbors which comes from our common Communion with Christ.
1Cor 10:18-21 said:
Behold Israel according to the flesh. Are not they that eat of the sacrifices partakers of the altar? What then? Do I say that what is offered in sacrifice to idols is any thing? Or that the idol is any thing? But the things which the heathens sacrifice, they sacrifice to devils and not to God. And I would not that you should be made partakers with devils. You cannot drink the chalice of the Lord and the chalice of devils: you cannot be partakers of the table of the Lord and of the table of devils.
A sacrifice is completed -- Jewish, pagan or Christian -- when those present partake of the sacrificial victim. It is that way in which they participate in the sacrifice, in which we participate in the Sacrifice of Christ and partake of the Risen Lord, receiving His Grace.
nor would it have been the bread that Jesus ate with His disciples. There was no white flour then - it would have been whole grain flour and may have been any variety of grain or grains.
The ancients had white bread. In the 19th c., industrialization made it more readily available but it was always possible to make white flour, it's just a mechanical process of milling or boulting to separate the components. This is not to say that it
was white bread but white bread was certainly available. It must, however, be made of the finest available wheat and fresh -- suitable for the King.
I never knew there was a "rubric" for communion bread.
And as far as "proper" - really, all we know for sure is that it was unleavened bread.
Do we now?
Mt 26:17 said:
And on the first day of the Azymes [ἀζύμων - unleavened bread], the disciples came to Jesus, saying: Where wilt thou that we prepare for thee to eat the pasch?
But does Christ eat unleavened bread?
Mt 26:26 said:
And whilst they were at supper, Jesus took bread [ἄρτον - leavened bread] and blessed and broke and gave to his disciples and said: Take ye and eat. This is my body.
Not a single one of the Gospels records Christ eating unleavened bread (ἀζύμων

at the Last Supper, rather He used leavened bread (ἄρτον

. On the other hand, others note that ἄρτον
can refer to unleavened bread, it is just generic and leavened is assumed (in English it is similar, if I said I was going to eat some bread, you would assume it would not be crackers but a normal, leavened loaf).
So therefore, it is ambiguous whether Christ ate leavened or unleavened bread at the Last Supper. However, it is irrelevant since both have been used in the Church since antiquity. In the West, the unleavened tradition prevailed and the East (with a few exceptions) maintained the leavened tradition.
Christ used
bread, size, shape, leavened or unleavened -- it doesn't matter. There is great symbolism and history behind both the Eastern (leavened) and Western (unleavened) traditions.
For all we know it could have been full of nuts and honey.
No, it couldn't have. How can you insist that it be unleavened because of the Passover regulations and then state that it could have been full of nuts and honey? Just pure wheat bread.
All this "rubric" and "proper form and matter" is man made rules and regulations.
Some yes, some no. For example, I can't decide to baptize someone with a glass of milk, that's not what Christ instituted, it would be invalid because of a defect of matter -- only water may be used. I can't decide to celebrate the Eucharist with a steak and a glass of beer. I can't marry a pig. I can't ordain a woman. Certain things -- those which
invalidate the Sacrament -- are instituted by God and thus are not "man made rules and regulations".
Those things which
are man-made, such as the method of baptizing (immersion, effusion, once or thrice), certain attributes of the Eucharistic elements (leavened or unleavened), the prayers used in the liturgy, etc. But this does not mean they are unimportant or can be dispensed with. They are part of the tradition of the Church, the means by which the faith is passed down and thus they are subject to the authority of the Church. Also, remember that "custom has the force of law" and cannot be changed haphazardly.
This is why using pita bread for the Sacrament is valid (it conforms to Christ's institution of the Eucharist, which necessitates only wheaten bread) but yet is illicit (because the Church has decreed that only unleavened bread be used within the Latin Rite). So therefore, the Sacrament is valid and it is truly Our Eucharistic Lord in the Sacrament but the celebrant sins in confecting the Sacrament with illicit matter.