Of course there are various hot butter sauces in French Cuisine, Beurre Blanc, Beurre Noir etc, but Beurre Brun! Non.
I've already expounded on Beurre Blanc which was designed for fish, but my wife's not keen on fish, fish fingers yes. So I thought I'd give it a go with meat, veal would have been ideal, but where's the veal in this mealy mouthed country, so I opted for pork. This is a trimmed loin steak, beaten out a little to become a pork escalope, pan fried. Now, hating to waste flavour (and getting colour into the bargain) I chose to deglaze the sauté pan with 2.5fl oz of vinegar and 2.5fl oz wine then reduce down to a tablespoonful, toss in the butter 12oz or 340g in chunks whisking as it melts. Result Beurre Brun, totally amazing sauce, and my wife cleared her plate, which is rare!