Beef Stroganoff | America's Test Kitchen

Ingredients

• 1 1/4 pounds sirloin steak tips , trimmed of excess fat and cut lengthwise (with grain) into 4 equal pieces (see note)
• 2 teaspoons soy sauce
• 1 pound white mushrooms , wiped clean and quartered (see note)
• 2 teaspoons hot water
• 1 tablespoon dry mustard
• 1 teaspoon sugar
• Ground black pepper
• 1 tablespoon vegetable oil
• 1 medium onion , chopped fine (about 1 cup)
• Table salt
• 2 teaspoons tomato paste
• 4 teaspoons unbleached all-purpose flour
• 1/3 cup plus 1 tablespoon white wine or dry vermouth
• 1 1/2 cups beef broth (see note)
• 1/2 cup sour cream
• 1 tablespoon chopped fresh parsley leaves or dill