Pickled ash keys is actually a fairly old recipe and a method of pickling them can be found in John Evelyn's Acetaria, a Discourse of Sallets written in 1699. Who goes on to say ' Gather them young, and boil them in three to four waters to extract the bitterness; and when they feel tender, prepare a syrup of sharp whitewine vinegar, sugar and a little water.Then boil them on a very quick fire, and they will become of a green colour, fit to be potted when cold'.
If that does not enlighten you to the process of picking ash keys you can always try this method:
Ingredients: Enough ash keys to fill your preserving jar, 3 tablespoons of brown sugar, teaspoon of salt, bay leaves, peppercorns and enough spiced pickling vinegar to cover the keys.
Remove the stalks and bring to the boil in a pan for 5 minutes, drain and then repeat process (allow to cool). In a bowl mix the spices, sugar, salt and pickling vinegar until dissolved. Pour the liquid into the jar with the ash keys, seal and store in a cool place.The pickling process will take about 3 months leaving ample time to figure out what to do with theses buggers!