Finally managed to make it to Thi Thi and try their famed subs. If you are confused by the two seemingly different menus side by side, it's ok I was too. I tried Googling the Vietnamese menu but it's actually just the exact same - except in Vietnamese.
They only have one vegetarian option which is basically just the toppings that all the other subs get. I got all the toppings (except mayo, which they will put on by default so if you're vegan or you don't like mayo be sure to tell them you don't want it). Everything blended really well together. I was surprised by how much I liked the little chili she cut up into the sandwich. It totally made my mouth kind of numb but somehow didn't induce crying?? Magical! Even the onions tasted good and I usually hate raw onions.
The only reason I'm not giving them 5/5 is honestly just the lacklustre vegetarian option. To non-vegetarians, this probably doesn't matter. Thai Tai on 17th - my favorite Vietnamese sub place still I think - has a tofu option that I prefer to the plain veggie one Thi Thi has to offer. Maybe if I'm lucky they'll consider adding some sort of tofu option in the future. I do think the quality of their subs is great and the most authentic tasting I've had in Calgary.