yer mate my last gym was full of hench body builders and giant fucking russians. This new family gym im at is full of fanny now lol. U need carbs throughout the whole day and night to grow though so if i was u i would first start of doing the abs for ten mins a day. Cardio will work but the amount u gotta do just to burn of a biscuit is stupid so you'd have to do cardio everyday. Just try abs mate for about a month while keeping your diet the same. Then if i doesnt work i'd try a bit of cardio then if that doesnt work i'd change diet.
But like u say u need carbs to grow. The best sort of carbs are brown rice and brown pasta and sweet potato iirc try not to eat potato unless its straight after workout or at lunch time etc.

I.ve never had abs before and always love handles but doing abs worked my belly so well its flat and hard now, so hopefully some definition will soon appear