Red Wine Pan Sauce with Mustard and Thyme

Follow related recipe for Pan-Seared Steaks. To same skillet used to cook steaks (do not clean skillet or discard accumulated fat), add shallots and sugar off heat; using pan’s residual heat, cook, stirring frequently, until shallots are slightly softened and browned and sugar is melted, about 45 seconds. Return skillet to high heat, add wine, broth, and bay leaf; bring to boil, scraping up browned bits on pan bottom with wooden spoon. Boil until liquid is reduced to 1/3 cup, about 4 minutes. Stir in vinegar and mustard; cook at medium heat to blend flavors, about 1 minute longer. Off heat, whisk in butter until melted and sauce is thickened and glossy. Add thyme and season to taste with salt and pepper. Remove bay leaf, spoon sauce over steaks and serve immediately.