Terry Pratchett, a comic fantasy writer, has something on the planet he calls discworld called Wow-wow sauce. His version is made of scumble (don't ask), pickled cucumbers, capers, mustard, mangoes, figs, grated wahoonie, anchovy essence, asafoetida, sulphur and saltpetre, and much else besides. It's quite a nice sauce, although it can't be eaten near a naked flame.

There is also a real-life version, that supposedly goes pretty well with a steak. I haven't tried it, since I don't have any skill in the kitchen whatsoever, but feel free to try.

Wow-Wow Sauce

Ingredients:

A lump of butter (or substitute) about the size of an egg.
1 tablespoon plain flour.
half a pint of beef stock.
1 teaspoon of english mustard.
1 dessert spoon of white wine vinegar.
1 tablespoon of port (the alcoholic drink, yeah?).
1 tablespoon of mushroom concentrate (see below).
1 heaped tablespoon of freeze-dried parsley.
4 chopped pickled walnuts.
salt & freshly ground black pepper to taste.

Method:

Melt the butter in a saucepan. Stir in the flour and work in the beef stock. Keep stirring on a medium heat until you have a thick but smooth sauce.
Stir in the mustard (made up!), the wine vinegar, the port and the mushroom concentrate. Sprinle on some salt and black pepper, and then cook for another 10 minutes or so.
Then add the parsley and walnuts, warm them through and then it's ready to serve.

It's supposedly pretty good, since my source for this says "We are unable to comment on its keeping qualities - the question has never arisen." There's a long list of substitutes given- pickled cucumbers and capers instead of walnuts, worcestershire sauce instead of mushroom concentrate and port, and changing the vinegar and mustard can change the taste a lot.

Mushroom Concentrate

Put 6 large button mushrooms into a bowl and sprinkle them with salt. Leave them for 3 hours, then mash them up. Cover the bowl and leave overnight. Drain the liquid into a saucepan, and try to put the mushrooms through a sieve to get more of it. Boil the liquid, stirring constantly, until you have half of what you started with. That should give you about a tablespoon of mushroom concentrate.

There you have it.....taken from the Discworld Companion, it should be pretty good. Not exactly a fine-tuned recipe, so experiment and change it all you like.