Go back many years and do the silver-foil covered spuds spiked to make 'hedgehogs' of cheese, silverskin onions, prawns etc. etc.. All cold and prepared beforehand.
Frankly, it's as easy to visit 'Iceland' and buy a few packs of prawns in filo, sausage rolls etc., etc., etc.. Cook them in the oven allow to cool and there you are.
Smoked salmon and cream cheese in celery stalks. Curried eggs hard boiled scoop out yolks, mix with mayo and curry powder put back in eggs. Ready made meat balls with dipping sauce