Roast fillet of beef with mushroom stuffing

INGREDIENTS

• 25g dried porcini mushrooms
• 400g wild mushrooms
• 200g shallots
• knob of butter , plus extra for roasting
• 2 tbsp olive oil
• 1 garlic clove , crushed
• 2 thyme sprigs
• 1.5kg/3lb 5oz beef fillet
• 1 tbsp plain flour
• 3 tbsp brandy
• 400ml hot beef stock
• 2 tsp wholegrain mustard
• 2 tbsp crème fraîche
• handful parsley , chopped