Chicken Cumberland pie with pumpkin topping

Ingredients

• 1 tablespoon olive oil
• 1 onion, finely chopped
• 1 parsnip, finely chopped
• 1 carrot, finely chopped
• 500 gram chicken mince
• 2 garlic cloves, finely chopped
• 2 teaspoon thyme leaves, plus 4 extra sprigs
• 1/4 cup plain flour
• 1 1/2 cup chicken stock
• 1/2 cup milk
• 1 bay leaf
• 1/2 cup frozen peas
• 1 tablespoon Worcestershire sauce
• 1/2 cup fresh breadcrumbs
• Pumpkin topping
• 750 gram butternut pumpkin, peeled, chopped
• 10 gram butter