Here is a jam recipe.
I tried it last year as I was given so many of them.I wasn't very keen on it, though Darrell liked it and used to eat it with cheese and salami.
4lb cucumber
4lb sugar
to each pint of juice and pulp, add 1/2oz root ginger and rind, pith and juice of 2 lemons
Peel and slice the cucumber, place it in a pan with the rind, pith and ginger [ in a muslin bag] and cook gently to produce a medium pulp, then add the sugar and the lemon juice,boil and pot.
My Bulgarian friend,grates her spare cucumbers and then freezes them so she can make tarrator in the Winter.