Ingredients

• 4 tbsp olive oil
• 6 sage leaves
• 3 onions
• peeled and finely sliced
• 250g/9oz ready-rolled all-butter puff pastry
• 3 large cooked leftover roast potatoes (or boiled potatoes)
• quartered
• 150g/5½oz gruyère

Directions

• Preheat the oven to 190C/170C Fan/Gas 5.
• Put the olive oil and sage leaves in a pan. Fry until crisp and then immediately remove the sage leaves and set aside.
• Add the sliced onions to the same pan. Cook over a low to moderate heat for 20-30 minutes
• stirring occasionally
• until soft and caramelised. Set aside.
• Lay the puff pastry out on a lined baking tray and top with the caramelised onions
• leaving a border all around. Top with the potatoes and grated gruyère. Bake for 20-25 minutes.
• Remove from the oven when golden-brown
• garnish with the crisp sage leaves and serve.