Beef Stroganoff with Button Mushrooms

Ingredients

• 1 tablespoon vegetable oil
• 10 ounces beef (sirloin or fillet) cut into 1/3” wide strips
• 1 tablespoon butter
• 1 small onion, diced
• 9 ounces button mushrooms halved (quarter if they are large)
• 1/4 cup dry white wine
• 1 tablespoon tomato paste
• 1 teaspoon whole grain mustard
• 3/4 cup beef stock
• 2 teaspoons flour
• 1/4 cup sour cream

Instructions

1. 1
   Add the oil to a frying pan and heat over medium high heat. Generously salt and pepper the beef. When the pan is hot and the oil is shimmering, add the beef in a single layer and fry undisturbed until it’s browned on one side. Stir and fry until the beef is mostly cooked. Transfer to a bowl.
2. 2
   Add the butter to the pan and when it’s melted, add the onions. Fry until they are soft and starting to brown. Add the mushrooms and continue frying until they are cooked through and any liquid that came out of the mushrooms has evaporated.
3. 3
   You should now have a good deal of brown fond stuck to the bottom of your pan. This is what gives the stroganoff it’s flavor, so add the wine, and scrape up those browned bits into the wine.
4. 4
   Boil the wine until most of the liquid is gone, and then add the tomato paste, mustard and beef stock. Boil until this mixture has reduced by half.
5. 5
   In a bowl, whisk the flour and sour cream together until there are no lumps.
6. 6
   Turn down the heat and return the beef to pan along with any collected juices. Add some of the hot liquid into the sour cream mixture and stir to combine. Repeat until the sour cream mixture is lukewarm. This prevents the sour cream from curdling when you add it to the pan.
7. 7
   Add the sour cream mixture to the pan and quickly stir to distribute. The stroganoff is done when the sauce has thickened up.
8. 8
   Serve with egg noodles, potatoes or rice.