You could do it in 3 different ways. No need to buy some extra tools.
You can use a cake/pie server, spatula or turner or the big kitchen knife blade and here is how:
1) Use a large knife and transfer the vegetables / objects on to the side of the knife blade by using a wood, plastic or teflon spoon, cake/pie server, spatula or turner. If you do not have it in other then of metal then use one of metal, but metal could scratch your knife blade.
You could use your hand instead too, to push the vegetables / objects on the knife blade too, just watch out so you do not cut yourself by accident on the knife blade.
2) Use a large cake/pie server, spatula or turner and then transfer the blade over the pan or object you want to ditch your vegetables / objects in. If you have no cake/pie server, spatula or turner, then just use what ever you have in the kitchen that looks more or less like a large flat thin surface.
3) Put the board near the edge of the table and simply put the pan under that edge and push the vegetables / objects using the knife you cut it with. Of course for this you need to have the pan cold, not hot, so you do not burn yourself.
PS: It looks like there are those who have a lack of imagination, so there for I need to be MORE specific. Example if you do not have a specific pallet for such, do not buy one, use a cake pallet or a big spoon or a blade of some sort, that would work too.
Use something like
NOTE: You do not need to buy anything, just see what you have at home that has a flat and clean surface and has a good in size and is thin and enough hard/durable enough to carry the vegetables / objects you cut.