Hendersons Relish, boy that takes me back! It's a bit of a South Yorkshire/Sheffield speciality rather than a "Yorkshire" one. My Nan and Grandad in Sheffield always had it on meat & potato pie - they used to get it from the local shop on "draught", take in an empty bottle and have it filled from a huge barrel of the stuff. I've not found it anywhere here in Leeds though - maybe it doesn't "travel" (like Tetleys) ??