What about taming Wolves? Bones do sometimes drop from Stone, but you DO have Fertilizer and stuffs, so what about Dog Biscuits for obtaining man's best friend? Made with 4 Dough (used also to make Seitan) in a diamond shape surrounding 1 raw meat if you don't know what the heck this mod is about, or, if you're full vegan, Rotten Plants. (Hopefully this is better than my other suggestions... :P)

Maybe as well, there should be a method of taming Ocelots, since you have the Frozen Bubble for Pufferfish. A Ball of Yarn would be made with 9 Kapok Tufts, giving you 4, and would tame Cats.

I like it. I was thinking about this recently--whether or not Seitan should have the 'wolves favorite food' flag enabled or not. I like this idea better, though, as it's easier to understand.

Why not both? It appears dogs like seitan too.

The only reason I'm reluctant to do that is because the 'wolves favorite food' flag is generally used as an 'is meat' flag in other mods (and this mod), and so adding that flag to seitan might make other mods treat it in ways that it shouldn't be treated. Creating a separate item that's specifically for wolves at least partially removes the possibility for conflicts, or makes them less of a problem.

I'm not really sold on the recipe in the OP, but I like the idea behind it.

Excellent idea @elifoster

I don't think it's a good idea to set the favorite food flag on any of the vegan foods. Instead, it might be better to have an interface IWolfVeganFood or something, subscribe to the PlayerInteractEvent, check if the item implements that interface, and tame the wolf. That way you don't run the risk of certain items being treated as meat in other mods, but you still allow the player to tame wolves.

On another note, catnip.