If you leaf through old cookery books from the 60's and 70's, you will find illustration after illustration of bizarre looking dishes covered in a thick layer of aspic jelly. Tastes have changed, but, now and again, I think there's still a place for using the stuff.
A few years back, I was lucky enough to sample some canapes at the Hotel Crillon in Paris; they were utterly delicious; tiny crutons topped with all sorts of goodies set in a rich meaty aspic, which melted smoothly on the tongue. Most of those retro recipes called for a packet of aspic. I've a feeling that packet aspic has either been banned in the EU, or it's just not made anymore because of a lack of demand. In any event, it's probably a better idea to make your own aspic, as the packet stuff had a similar texture to industrial rubber.
If you want to make your own aspic, here's how you do it: Make a brown stock in the usual way. Leave it to cool, and then skim off all the fat. Pour four cups of the stock into a decent sized pan, and add two tablespoons of white wine vinegar, a bouqet garni, the whites and crushed shells of two eggs, four tablespoons of white wine, and 40-50g of gelatine. (You can buy leaf gelatine in wafer-thin strips which you need to break up into small pieces.)
Bring to a near boil very slowly, whisking the whole time. (It might be a good idea to melt the gelatine in a separate pan first (ie a bain marie), as you will find that it sets very quickly). A thick crust should develop at the top of the pan. This is a good thing, and will help to clarify your stock. Stop whisking for a minute, and let the liquid rise up to the top of the pan.
Finally, strain the liquid through a muslin cloth, trying to keep the crust intact, as it will act as a filter. Strain the aspic a second time, and you should end up with a crystal clear liquid, that will set- and become- trumpet fanfare- aspic...