I don't usually give anything specific for a GS, but more and extras of all sorts of things including fruit (definitely bananas he will ask for one as soon as he is up if he's having GS), veg, crackers, muesli, oaty chews (flap jack type sugar free thing)
I did cook up lots of cocktail sausages during a GS at 3yo though, I cooked them all in one go then froze them and lifted several out each day.