I just throw a bit of cooking Madeira into the cooking juices, really, just before serving... I just eyeball it, and have to admit I completely forgot to buy the stuff this year, haha. So just ducky juice with the breasts this year, which should still be good. Most proper sauces have a thickening agent that's a no-go for me. but if you want something as it should be, the super market sells it ready made this time of year.
. I don't think there's a lot of Jumbo's up north, but I'm sure there's similar super markets out there in the sticks.
Tried to post this with links, but the forum wouldn't have it for some reason...