Method

• 1.
  For the gratin, heat 1/3 cup (80ml) olive oil in a large frypan over medium heat. Add the onion and garlic, then season with 1/2 teaspoon salt and some freshly ground black pepper. Cook, stirring regularly, for 20 minutes or until the onion is lightly caramelised. Adjust seasoning, if necessary, then set aside.
• 2.
  Meanwhile, season the potatoes with sea salt and freshly ground black pepper. Heat 1 1/2 tablespoons olive oil in a deep non-stick, ovenproof frypan (or use a regular frypan, then cook the gratin in a baking dish). Pan-fry half the potatoes for 6-8 minutes, turning, until they are lightly golden and almost tender. Transfer to a bowl. Add another 1 1/2 tablespoons oil to the frypan and repeat with the remaining potatoes.
• 3.
  Remove the frypan from the heat. Layer one-third of the potatoes in the frypan or baking dish and cover with half the caramelised onions. Sprinkle with half the thyme leaves and season with sea salt and freshly ground black pepper.
• 4.
  Repeat the potato, onion and thyme layers, season, then finish with a layer of potatoes. Pour over stock, then cover with a lid or foil. Cook over medium heat for 25-30 minutes until all the stock is absorbed and the potatoes are tender.

• 5.
  Meanwhile, preheat a grill to high and the barbecue hotplate to medium-high.
• 6.
  Drizzle potatoes with remaining oil and place under the grill for 2-3 minutes until the top is crisp and caramelised. Keep hot.
• 7.
  Brush snapper with oil and season well on both sides. Grill snapper on the barbecue hotplate for 2-3 minutes on each side until lightly charred and cooked through. Sprinkle with the pimenton, then serve with the potato gratin.