[quote="vegan hal"]i don't worry about abs really myself. but I was always under the impression that it would be best to first pack on some muscle and fat, then it's easier to lose the belly fat later with dieting and some cardio.
I would agree with that.
Visible abs are all about low body fat, and that is largely through diet. Generally, the lower the carbs, the lower your body fat will go, but there are diminishing returns somewhere in there. It's hard to train a lot if you are only eating protein and veggies (in my experience), so if you want to get big, do that first, and then worry about shedding any excess fat you may have acquired.
Tim Ferriss' Four Hour Body has some good tips on this, though he is anti-soy and not vegan.