Veganism, as a philosophy, is not compatible with Catholicism.  It is evil and closely linked to other evils promoted by leftists.

You are SO off base here.
There are many reasons people choose not to eat meat.  From what I have experienced, the majority of vegans eat this way due to the grossness of our meat.  Look at the videos!  You are eating that!  GROSS.
There are vegans who eat vegan for medical reasons, and I can see where this may be correct.

The few who eat vegan to oppose the Bible are VERY few.

Aren't there some Franciscans or maybe other Catholic orders who have refrained from eating meat? It seems like I've read that somewhere. 

Aren't there some Franciscans or maybe other Catholic orders who have refrained from eating meat? It seems like I've read that somewhere.

I believe the minim order does.  And, I think the founders name was Francis.  

Tomas of Celano, biographer of St. Francis tells this story:

“Francis observed the birthday of the child Jesus with inexpressible eagerness over all other feasts, saying, ‘It is the feast of feasts, on which God, having become a tiny infant, clung to human breasts.’ When the question rose about eating meat that day, since Christmas was a Friday, he [Francis] replied to Brother Morico, ‘You sin, brother, calling the day on which the child is born to us a day of fast. It is my wish that even the walls should eat meat on such a day; and if they cannot, they should be smeared with meat on the outside.’”

The medieval heretical sect, the Cathars, totally abstained from meat.

I believe the minim order does.  And, I think the founders name was Francis.  

I looked up the Minim order, and the order was approved in 1506 by Pope Julius ll. The rule was approved, which included veganism, except in case of grave illness, or by order of a physician. The Order was founded by St. Francis of Paola. He seemed like a good and saintly man.

https://en.wikipedia.org/wiki/Minim_(religious_order)

BTW, I'm not a vegetarian or vegan.

Evidently, according to the Wiki article, the minims also brewed beer at one time. Paulaner beer takes its name from St. Francis of Paola.

The Wikipedia article on the Minim order explains their reason for abstaining from meat:

In addition to the standard three religious vows of chastity, poverty and obedience, the Rule contains the vow of "a Lenten way of life" (Latin: vita quadragesimalis), which is considered to be the distinctive feature of the Minims.^[5] This vow is for perpetual abstinence from all meat and dairy products, veganism, except in case of grave illness and by order of a physician. Because of asceticism, The Order is also discalced in character and there are other acts of humility.

Note that there is no suggestion that there is anything wrong with eating meat.  It was a spiritual discipline of adopting Lenten practices throughout the year.  

This is different from philosophical vegans who believe it is wrong to take animal lives.  It is also different from those who avoid meat believing it to be unhealthy.

I find veganism interesting and am sympathetic towards it. I can understand not wanting to promote cruelty towards animals and also the environmental concerns. And also eating simpler foods for spiritual reasons though I don't think most vegans are vegans for this reason. I mean many monks in the past would not eat much meat. Sometimes I think my ideal diet would be to eat nothing but potatoes, but I don't think that would be healthy so I have never tried it. But I do try to avoid eating a lot of meat.

If you like potatoes, I recommend you make sure you buy organic with that food.  Non organic potatoes are almost always sterile.  They do not produce flowers/fruit and cannot reproduce themselves.  Organic potatoes will grow flowers and can therefore reproduce themselves.  All farmed potatoes (organic or not) are clones.  The only place I found selling true potato seeds online is ukraine, which means they may be the only place using them.  If the irish were growing their potatoes from true seed rather than cloning, it is much more likely the potatoes would not have failed.  Just like with human degrees of consanguinity, plants need genetic diversity.