Red red wine
A reduction of equal parts red wine and beef or chicken stock is rich and satisfying. Soften sliced shallots, crushed garlic, a touch of rosemary and balsamic vinegar, before adding the wine and stock. A knob of butter adds richness.
Mustard and mushrooms, mmmm
Soften mushrooms and garlic, add a slosh of sherry and a sprig of thyme, stir in beef stock and reduce. If you like your sauces creamy, add a couple of dollops of creme fraiche and a grainy mustard for a sharper bite. Or skip the mushrooms and just add white wine, beef stock and green peppercorns to the pan juices, with a slosh of mustard and cream.
De-glaze the steak pan with a good rich beef stock, stir through thick cream and crumble in a stinky blue cheese for a pungent sauce for your best steak.