Mushroom & Chicken Pot Pies

Ingredients

• 300 g button mushrooms, sliced 1cm thick
• 500 g chicken thigh fillets, diced
• 2 tbsp olive oil
• 20 g butter
• 1 onion
• 3 cloves garlic, chopped
• 4 sprigs thyme, leaves only
• 1 leek
• 1 tbsp plain flour
• 300 ml cream
• 2 tbsp wholegrain mustard
• salt & pepper
• 4 sheets pastry
• 1 egg