It's parsley sauce...and here comes the but....the water they use to make it is the stuff left over from boiling the eels, so technically eel juice and parsley. What's not to like?
Pie and mash is nice enough if you're a heathen like me and opt for gravy instead of liquor.
in recent years I've noticed not many have the eels like they used to not the demand appentely , So most just use plain water .
years back it was eel juice and eel pies mmmm that's proper choppy but eels went off the menu in the decline so mince beef took over ,don't think theres many that use eel juice now w