Beef Stroganov

Preparation

1. Step 1

   Melt 1 1/2 tablespoons butter in a small heavy saucepan over moderate heat and whisk in flour, then cook roux, whisking constantly, 2 minutes. Add broth in a slow stream, whisking constantly, and bring to a boil. Reduce heat and simmer, whisking occasionally, 3 minutes. Remove from heat and keep warm.

   Step 2

   Pat beef dry and season well with salt and pepper. Heat 1 tablespoon butter with 1 tablespoon oil in a 12-inch heavy skillet over moderately high heat until foam subsides. Sauté beef in two batches, turning once, until browned on both sides but still pink inside, about 1 minute. Transfer to a plate with a slotted spoon.

   Step 3

   Heat remaining tablespoon butter with remaining tablespoon oil in same skillet over moderately high heat until hot but not smoking, then sauté shallot, stirring occasionally, until golden brown, about 3 minutes. Add mushrooms and sauté, stirring occasionally, until liquid mushrooms give off is evaporated and mushrooms are browned, about 8 to 10 minutes. Return meat with its juices to skillet and stir to combine, then transfer to a platter.

   Step 4

   Reheat sauce over low heat (do not let boil), then whisk in sour cream, mustard, dill, salt, and pepper. Pour sauce over beef and serve immediately.