Classic Beef Stroganoff

Ingredients

• 2 2½ lbs boneless sirloin, trimmed and cut into thin strips
• ½ cup flour
• 1 tsp salt
• 1 tsp freshly ground black pepper
• 4 tbsp butter
• 3–4 shallots or 1 onion, thinly sliced
• ½ lb mushrooms, thinly sliced
• 2 cups beef or chicken stock
• 2 tbsp dry mustard
• 1 tbsp smoked paprika
• 2 tbsp sweet paprika
• 1 cup sour cream
• 1 tbsp sherry
• 1 tsp Dijon mustard
• 1 tbsp Worcestershire sauce
• Pinch freshly grated nutmeg
• 3 tbsp finely chopped parsley
• 3 tbsp finely chopped dill
• Crispy onions and buttered noodles or rice, to serve