One-pan chicken and vegetable skillet pie

Ingredients

• 1 litre chicken stock
• 1/2 bunch dill, fronds chopped, stalks separated
• 1/2 bunch parsley, leaves chopped, stalks separated
• 2 bay leaves
• 2 chicken breasts
• 60 gram butter, chopped
• 1 leek, trimmed, sliced
• 3 spring onions, sliced
• 4 garlic cloves, sliced
• 1 courgette, sliced
• 100 gram sugar snap peas, sliced
• 1/4 cup cornflour
• 1/4 cup water
• 1/2 red capsicum, seeded, finely sliced
• 6 sheets filo pastry
• 30 gram butter, melted
• mixed salad leaves to serve