empty wine into a pot and warm on the stove (just so that it feels warm, not anywhere near boiling)
dissolve/soak gelatin according to packet instructions.
powder - usually they like you to dissolve in warm liquid, so you can put this straight into the wine if you like. 10 g gelatine does 500 mL of liquid, which will be enough to serve 4.
leaves (or sheets, as they're sometimes called) - these need to be pre-soaked for about 7 minutes in a bowl of cold water, then slightly squeezed before popping into your liquid. usually 1 leaf will set 100 mL of liquid (where each leaf = 2 g).
stir warmed wine until gelatin is completely dissolved
drain the cherries from the syrup and divide the evenly into ramekins or whatever you're using as jelly dishes
pour the warmed solution over into each ramekin
chill in refridgerator until set (usually 4 hours)
in winter, you can heat up some custard and serve as a sauce over the jelly..... mmmmm!
* you can make this any kind of wine or alcohol combination e.g., a dash of port or use vodka instead) the important part is to have the correct proportion of gelatin for the volume of liquid you are using