Beef Stroganov

Directions

1. 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.
2. 2
   Add broth in a slow stream, whisking constantly, and bring to a boil.
3. 3
   Reduce heat and simmer, whisking occasionally, 3 minutes.
4. 4
   Remove from heat and keep warm.
5. 5
   Pat beef dry and season well with salt and pepper.
6. 6
   Heat 1 tablespoon butter with 1 tablespoon oil in a 12-inch heavy skillet over moderately high heat until foam subsides.
7. 7
   Saute beef in two batches, turning once, until browned on both sides but still pink inside, about 1 minute.
8. 8
   Transfer to a plate with a slotted spoon.
9. 9
   Heat remaining tablespoon butter with remaining tablespoon oil in same skillet over moderately high heat until hot but not smoking, then saute shallot, stirring occasionally, until golden brown, about 3 minutes.
10. 10
    Add mushrooms and saute, stirring occasionally, until liquid mushrooms give off is evaporated and mushrooms are browned, about 8 to 10 minutes.
11. 11
    Return meat with its juices to skillet and stir to combine, then transfer to a platter.
12. 12
    Reheat sauce over low heat (do not let boil), then whisk in sour cream, mustard, dill, salt, and pepper.
13. 13
    Pour sauce over beef and serve immediately.