Hi - I'm not familiar with Letterman, not sure if it's shown in the UK? But Sole a la Meuniere is a classic, so it won't change much. The almonds are bling, but so is my suggestion of preserved lemon. It works because it's simple and the main thing is to get the brown butter right.

I imagine any flatfish might work although it might be a waste of Turbot, but Dover Sole is generally considered to be the best - and very expensive. I'm lucky in that our nearest fishmonger in Morecambe has his own boat, but the soles that I buy are smaller than those that a restaurant might sell (if they can get them).
Interestingly (no, really!), Dover Sole is apparently one of the few fish in which the flavour will develop over 24 hours, so best not to eat it absolutely fresh. I confess that I've never kept one till the next day.