In well under an hour, this fast beef stroganoff recipe is ready to make its dinner debut. Quick-cooking strip steak is briefly frozen to make slicing a breeze, and then it cooks in under five minutes. Next, a mixture of mushrooms like oyster, cremini, and shiitake, plus onions and beef broth, come together for a rich sauce, thickened with a sprinkle of flour. The sauce is finished with sour cream for a little tang and fresh dill for brightness. It’s a weeknight masterpiece.