If not eating meat is a moral choice as you say, i.e. you use to eat meat, and now you've realized the eating of meat is morally wrong, then the fashioning of a sandwich that allows you to look back at your past moral failings with fondness strikes me as a very odd thing to do.
I'm not saying you are odd as a total person, just the single practice you are describing here.
Sure it's not immoral to eat the non meat sandwich today, of course not. ...but to make the sandwich so that it purposefully reminds you of past crimes you committed against animals, seems like something you'd want to avoid, not seek out because it makes you feel good.
As an analogy...say i'd been smacking my kid regularly up until they were 9 (i don't have any children, but just go with me here)... once they hit 10 I realized what a monster i was and vowed I'd never to do it again because it was morally abhorrent.
You'd say good for me presumably.
But what if i said, i got a large doll that looked like my kid and I enjoyed smacking it just to get in touch with the feelings I used to have when I was smacking my kids for real. It's not immoral to smack a doll... you're not harming any kids in the process. But it'd be a weird thing for me to want to do don't you think?
If you become a vegan the first thing you have to do is forgive yourself for the past mistakes, accept them. This is the key concept that I don't think you're seeing ... my previous reply was informative enough ...
I'm sorry I can't help you understand why a vegan would crave a certain dish from his past :)
My suggestion is to try it for yourself (go vegan!), that's the best way to understand it <3
sooo eating a sandwich with real mortadella is like beating up your kid (the kid feels pain) and eating that same sandwich with vegan mortadella is like beating up a doll (can't feel pain) ... it's an odd comparison, but completely on point (pain wise) ... i'm not sure i care why you'd beat up the doll, if it's weird or not, but i'm 100% positive i'd rather have you beat the doll instead of the kid :D
btw i think it's worse to eat meat than to beat up some1 else :D since the animal has to die first :P
also most ppl that eat meat don't kill animals themselves :P they pay for the final product, they like to eat the final product not raw meat ... so if the final product can be made meat free and you can eat it with peace in your heart ... why wld you NOT do it ? cuz it will "remind you of past crimes" ? really ?