Method

• 1.
  Preheat oven to 220°C. Place half the butter and half the olive oil in a medium saucepan over medium-low heat. Add onion and garlic, and season. Cook for 20-25 minutes until softened and lightly caramelised. Set aside.
• 2.
  Heat remaining 1 tbs oil in a 27cm ovenproof non-stick frypan over medium-high heat. Add tomatoes and cook, stirring occasionally, for 8-10 minutes until blistered and starting to release their juices. Remove from pan using a slotted spoon and drain on paper towel to absorb any excess moisture.
• 3.
  Place manchego and breadcrumbs in a small bowl. Mix to combine. Set aside.
• 4.
  Wipe frypan clean and place over medium heat. Add sugar, vinegar and remaining 30g butter, and cook for 3-4 minutes until sugar has dissolved and mixture has thickened. Remove from the heat. Add tomatoes in an even layer and season. Scatter over marjoram, spoon over caramelised onion and sprinkle over breadcrumb mixture.
• 5.
  Cut pastry into a 28cm round. Place over the tomatoes and breadcrumb mixture and use a small spatula to tuck the edge of the pastry under. Use a small sharp knife to make two incisions in the centre of the pastry. Place frypan on a large baking tray and place in the oven. Cook for 40-45 minutes until the pastry is puffed and dark golden. Remove from the oven and set aside for 5 minutes to cool slightly.
• 6.
  Carefully invert tarte tatin onto a serving plate. Top with chervil and extra marjoram leaves, and scatter with salt flakes and freshly ground black pepper to serve.