One-Pot Simple Chicken & Leek Pie - Simply Veg

Ingredients

• 2 leeks, washed well and sliced
• 2 garlic cloves, peeled and crushed
• 1 tbsp oil
• Salt & pepper, to taste
• Cooked chicken (leftovers from a roast are perfect here, ideally a large handful per serve)
• 150ml chicken stock or water
• 1 tsp mixed dried herbs
• 250g creme fraiche (you can use cream cheese if you prefer)
• 1 heaped tsp wholegrain mustard
• Frozen peas (a large handful per serve)
• 1 sheet puff pastry (300g, rolled)