BBC Food - Recipes - New England-style clam chowder with crunchy thyme breadcrumbs

Ingredients

• 1 tbsp olive oil
• Knob of butter
• 1 onion , peeled, finely chopped
• 2 celery sticks, finely chopped
• 2 bay leaves
• 2 sprigs fresh thyme
• 1kg/2¼lbs clams
• 1 ear sweetcorn , kernels sliced off and reserved
• 500ml/17fl oz chicken stock
• 300g/10½oz red potatoes , cut into pieces
• 100ml/3½fl oz single cream
• Handful fresh parsley , chopped
• Salt
• freshly ground black pepper
• 1 slice spelt bread
• 1 lemon , zest only
• 4 slices pancetta