Inwood isn't the most vegan-friendly neighborhood (lots of fast food and Dominican food, which is known for being meat-heavy), so Thai is always a pretty safe bet. Yummy Thai doesn't offer mock meats but they offer the usual veggie and tofu assortments of curries, noodles, and rice dishes.
I was in for lunch last week so I wanted to take advantage of the $7 lunch special. While the menu was somewhat unclear to me about which combinations were part of the special, the waitress explained everything to me. Basically, you could get veggies and/or tofu with any "sauce", which included various curries or noodle options. I usually get pad see ew in Thai restaurants so I went with the "Siracha" noodles. I love noodles and I love Siracha, so this was a no-brainer.
The tofu and veggies were good (the tofu was firm and slightly pan-fried), but I found the noodles to be overcooked and the sauce bland. It tasted like they put some generic "Asian sauce" (soy sauce and garlic) and Siracha and called it a day. Not particularly interesting.
That said, the staff was friendly, the ingredients were fresh, and the restaurant is attractive and welcoming so I'd go back to try their pad see ew.