sooooooooooo didn't you choose a menu after the PS? since vegan is (obviously) more considered than "just" vegetarian, i would talk with a chef. what are you having as of now? because you certainly could have just a plate for the one guy, but other dishes - i'm sure the chef could recommend or tweak what you are already having to add some vegan options. like we had our brunch, omelettes to order, mickey waffles, etcc and a pasta dish (vegetarian) and some side veggies, fruit. i felt like that was enough to cover the couple of vegetarians we had. so your planner could recommend adjustments or get you in tough with the chef! desserts are always a bit more tricky - you are quite a fabulous couple to consider a vegan cake (unless you guys are vegan too!!) - caue i'm not sure i could give up my cake and buttercream frosting!!!! but even if you don't do the whole cake, i'm sure you can get something or cupcakes from babycakes as an extra!
i need cake right now come to think of it!