Beef Stroganoff Recipe – Marion Kane, Food Sleuth

Ingredients

• 1½ lb/750 g beef tenderloin
• 1 lb/500g mushrooms, halved
• ½ tsp each: Salt and freshly ground black pepper
• 3 tbsp vegetable oil
• 1 small onion, peeled, chopped
• 1 tbsp all-purpose flour
• 1 cup beef or chicken stock
• 1 tbsp Dijon mustard
• ⅓ cup sour cream or plain yogurt
• Salt and freshly ground pepper to taste
• Chopped fresh parsley