Beef Stroganoff (From the "old" Russian Tea Room) Recipe - (4.3/5)

Ingredients

• 1 pound lean boneless sirloin (trimmed of fat and gristle) or 1 pound bottom round steaks, in one piece (trimmed of fat and gristle)
• 1 teaspoon salt
• 1/4 teaspoon fresh ground pepper
• 2 tablespoons butter
• 1/2 medium onion, thinly sliced
• 1/2 tablespoon flour
• 1/2 teaspoon mustard powder (OR 1 Tablespoon prepared Dijon style mustard)
• 1/4 cup dry white wine
• 1 teaspoon tomato paste (optional)
• 1/2 tablespoon minced onion
• 1/4 lb mushroom, thinly sliced
• 1 tablespoon dry white wine
• 1/2 cup sour cream, warmed