Beef Stroganoff in the Mellinkoff Manner

My very favorite stroganoff. The original recipe came from Ruth Mellinkoff's "The Uncommon Cook Book". The original recipe uses beef tenderloin, but to economize I use NY steak or beef sirloin (choice cut) .

• Ready In: 40 mins
• Serves: 6

Ingredients

• 3⁄4 lb mushroom, sliced
• 1  small onion, finely chopped
• 3  tablespoons butter
•  salt and pepper
• 1⁄2 cup sherry wine
• 3⁄4 teaspoon paprika
• 2  cups sour cream
• 2 -4  tablespoons lemon juice
• 2  tablespoons butter
• 2  tablespoons flour
• 1⁄2 cup  beef stock
• 2 1⁄2 lbs beef tenderloin or 2 1⁄2 lbs  New York strip steaks or 2 1⁄2 lbs  sirloin
• 1  tablespoon  oil (may need more)
• 1⁄4 cup sherry wine
• 1 1⁄4 tablespoons tomato paste

Directions

1. Saute mushrooms and onion in the 3 T butter and add salt and pepper. Cook 3 minutes and add the 1/2 C Sherry wine and stir. Slowly mix in the sour cream using a wire whisk and add the paprika, and lemon juice. Set aside.
2. In a small saucepan, melt the 2 T butter with 2 T flour. Add the beef stock over low heat and stir until sauce is very thick. Add this into the sour cream mixture.
3. Cut the meat into slices 2" by 1/4" and then season with some salt and pepper. Sear them quickly in the 1 T oil until browned on both sides and remove from the pan. Don't do too many slices at a time (it won't sizzle). Continue with remaining meat slices and remove from pan. Drain fat from the skillet and add 1/4 C sherry wine to the pan and deglaze.
4. Stir in tomato paste, sour cream mixture, and meat. Taste and add more salt, lemon juice or paprika as needed.
5. Serve over egg noodles.