The only sauces I currently have at home are soy and Worcester sauce.
I got some Henderson's Relish a while back. I'd not really had it despite it being a Sheffield thing and fairly local to me. They call it Hendo's there and Deedahs (Sheffield people) around the world take it with them or buy it online. It's been made for about 150 years about 100 yards from the original factory (just behind the big flats you see in The Full Monty).
It's a bit like an insipid Worcester Sauce without the kick. A bit like the very bland stuff they have in Germany and sell as Worcester Sauce. A sort of relation to Maggi.
It's good for vegans and I'd guess it would do as a substitute for a light soy sauce in cooking. Probably food with delicate Chinese recipes.
Never tried them. I doubt most people have
About Stargazy Pie, nobody outside Cornwall (where it was pretty well forgotten too) had even heard of it until about a decade ago when a theme park in China started selling it.
I like Dock Pudding (a Halifax specialty) and Herb Pudding (sort of Westmorland/south Lake District).
The latter is easy. Pearl barley, herbs (nettles are traditional, onion or leek, egg yolk and sometimes cream, baked in a mould.
Mushroom ketchup is nice. Rare in the shops and best home made.