Can I thicken sauce I've already made?

[Laugs]

Made a casserole for dinner last night, with enough left over to eat tonight as well.

The sauce wasn't as thick as it should have been. Is there any way of thickening the sauce when I reheat it tonight?

Thanks!

mix cornflour to a paste with a little water and add (with stirring) as you reheat

Get some cornflour, add water to make a paste (not too think). Add the paste gradually to the sauce when it's heating up, stirring it (you'll have to do this on the hob), until it's thick enough.

I think you can use arrowroot too but have never tried.

That was meant to say 'not too thick'

Great, thanks!