How to make a beurre blanc sauce
Peel and thinly slice the shallot. Place the shallot in saucepan with fresh thyme, dry wine and white wine vinegar. Reduce the liquid to one tablespoon and then reduce the heat. Start adding the butter, a little at a time and whisk continually to prevent the sauce from splitting. Once all of the butter has been incorporated, remove from the heat, season with salt and add a squeeze of lemon juice. Pass the beurre blanc through a sieve so that you are left with a thick and velvety butter sauce.