For the record, I did use my stock in the end.
Made a (I thought) pretty decent risotto bianco topped with some roasted summer veg. Was aiming for something lighter than the normal heavy risotto, which came out okay. I didn't add any salt since I was whacking a bunch of parmesan in there, plus the normal complaint about shop stock is that it's too salty. Anyway, the lass reckoned it was under-seasoned and added her own salt at the table, so it was a facepalm moment for me.
With the rest of the stock I made up some onion gravy for my favourite bangers and mash. It was nice, but it works just as well with the legendary marigold bouillon.
I think I'm gonna stick to decent shop stock. I know that making your own is really in vogue at the moment, because Jamie Oliver says it's cool, but boiling 5 litres of water on my stove for two hours is just too much for something I can get instantly and for pennies.