BBC Food - Recipes - Horseradish and mustard beef casserole

Ingredients

• 3 tbsp sunflower oil
• 1.5kg/3lb 5oz braising steak , diced
• 3 large onions , roughly chopped
• 6 garlic cloves, crushed or finely chopped
• 300ml/10fl oz beef stock
• 50g/1¾oz plain flour
• 300ml/10fl oz dry white wine
• 3 tbsp Worcestershire sauce
• 1 tbsp light muscovado sugar
• salt and freshly ground black pepper
• 500g/1lb 2oz chestnut mushrooms , halved
• 3 tbsp Dijon mustard
• 3 tbsp creamed horseradish sauce
• 3-4 tbsp double cream (optional)