Use same hot pan where a steak had been seared or cooked minutes before. Reserve the drippings in the skillet.

Add the shallot to the drippings and cook over medium heat until golden, about 2 minutes.

Add the wine and scrape up any browned bits with a wooden spoon. Bring to a boil and cook until reduced by half and slightly syrupy, about 7 minutes; remove from heat.

Whisk in butter, one piece at a time, to make a glossy sauce. Add salt and pepper to taste.

Serve over steak