Everybody, please learn from my mistake. Do not, under any circumstances, attempt to taste the roux you've been working on. Especially if you think you may have ruined it by burning it. No good will come of it.
I mean that rather literally, actually. You won't be able to taste if it's ruined. You won't be able to taste much of anything, because you'll scald the fuck out of your tongue, because that shit is hot.
And if you try to taste it off the whisk, you might sear a really impressive pair of white lines across your lip. I'd offer a photo for posterity, but I don't have a camera that's not way too much of a pain to use.
Also, if you think you might have ruined your roux, say by leaving it on the heat unattended at a critical moment because some sausages caught fire in your oven and you were distracted by dealing with that and trying not to kill the bird with the resultant smoke, you probably have. Just toss it and start over, and definitely don't bother trying to taste test it.
In other news, there's a cat on my desk nosing at my hand while I type, so I think I'm done here.