I always keep bones (chicken usually) and boil them up with some carrot and onion to make stock. I then put the (cooled) pan in the fridge, scrape off the fat that settles on top, reduce it further by boiling and when this sets wrap it up in clingfilm and stick it in the freezer.
I’ve got several of these little packets in there right now, all waiting to be turned into gravy, soup or a “jus” (excuse my French). I’ve just cycled back from town on my newly powdercoated stealth Soul with a load of fish bones and heads to make a lovely hake, mussels, wild mushrooms and scallops “nage” tonight.
Home made stock is much better for you because it contains no added salt. And tastes bootiful.
Anyhoo, assuming you are going the low fat route, Ton, I would just chop mushrooms, onions, carrots, and maybe celery, fennel (if you like an aniseedy flavour) and boil them up in either stock or plain water (white wine too would be good (I prefer Noilly Prat for this as it’s herby)
Strain off the veg after 30 mins or so then boil what’s left to reduce it until it tastes perfect.
Have it on its own, thicken with either cream, butter or flour if you’re on a day off, or use it as a stock for making a sauce with chicken fish or whatever.
