This classical French regional sauce is traditionally served with seafood, poached fish, and delicate green vegetable such as asparagus. It has only four simple ingredients that are apparent: the main ingredient is really time. You need to make this at a time when you really can dedicate yourself to standing at the stove. It's just one of those things in cooking that you can't really cheat at that way. The sauce truly is delicious, and you should enjoy it at least once in a while. Just enjoy it in small quantities, as it does pack a punch in calories: the main ingredient really is butterfat!
If it seems like a lot of shallot at the start, don't worry -- remember, there's a lot of butter coming. Most people advise to make this on the spot as needed, but that's not practical for home cooks who need to also cook something to serve this sauce on. So you'll want to make this in advance, the same day if possible, earlier that day. Don't put it in the fridge. To keep warm, put in a thermos, or, put in a jar with a lid on and set in a bowl of very hot tap water. The sauce will likely separate on you somewhat. A good stir should bring it back together easily. If it doesn't, then put a tablespoon in another bowl, and whisk it. Add another tablespoon, whisk it in. Repeat until all the sauce has been added into the bowl and whisked. If you need to make it a day ahead or have leftover, store that in a fridge in a sealed jar owing to the presence of the shallot in it. To reheat, reheat slowly by floating the jar (with its lid still on) in a bowl or pan of very hot tap water. Whisk to bring the sauce back together. Beurre Blanc Ingredients© Randal Oulton Beurre Blanc Step 1: Simmer the shallot in the wine and vinegar© Randal Oulton Beurre Blanc Step 2: Start adding the butter slowly in small amounts© Randal Oulton Beurre Blanc Step 3: Last of the butter goes inThe sauce is just about complete.© Randal Oulton