This video tells us the method to prepare a gourmet beef stroganoff. Take 3/4lb sirloin steak tip. Cover it with 1 teaspoon of soya sauce. Cover it and put in the refrigerator for 15 to 20 minutes. Take 1/2 teaspoon of mustard, 1 teaspoon of sugar and 1/4 teaspoon of black pepper. After this, heat 1/2 teaspoon of salad oil and let it smoke at medium high. Brown both sides of the meat. Take out the meat when the internal temperature registers 125 10 130 degrees fahrenheit. Add 1/2 lb mushrooms with 1 teaspoon of water in the pan. When all the water evaporates and mushrooms turn brown, add 1/2 yellow onion which is finely chopped and 1/4 teaspoon of salt. Add 1/2 teaspoon of flour, 1/6 cup white wine, 1 teaspoon tomato paste, 3/4 cup beef broth and mustard mixture. Simmer it till the sauce thickens slightly. Slice the beef and add to the sauce. Heat it for 1 to 2 minutes. Add 1/6 cup sour cream. Mix it properly and your dish is ready.