Griddled octopus with potatoes and olives

Ingredients

• 1kg prepared octopus (see tips)
• 1 bay leaf
• 2 fresh thyme sprigs
• 1 onion, roughly chopped
• 1 carrot, roughly chopped
• 1 celery stick, roughly chopped
• 1 garlic bulb, halved horizontally
• ½ tsp ground coriander
• ½ tsp whole white peppercorns (use black if you don’t have any)
• 10 large new potatoes (such as charlotte)
• Extra-virgin olive oil for drizzling and brushing
• 5 fresh mint leaves, chopped
• Grated zest 1 lemon
• 1 small onion, finely chopped
• Paprika to taste
• 10 green olives, pitted and sliced
• 2 tbsp chopped fresh flatleaf parsley