A crispy and flaky puff pastry tart with prosciutto cotto (Italian ham), oozy fontina cheese and potatoes. This tart is really easy to make, filling, satisfying and unbelievably delicious. Perfect for lunch, dinner or an antipasto.
Bring a large pot of water to a boil and salt it well. Pre-heat the oven to 180C/350F and line a large baking tray with parchment paper.
Wash and peel the potatoes then cut them into small cubes, about 1cm in size. Par-boil the potatoes in the boiling water for 10 minutes, then drain them in a colander.
Lay the puff pastry sheet on your baking tray. Using a fork prick a 1 inch border around the pastry then prick the inside of the base a few times.
Leaving the border free, lay slices of ham all over the base (I find about 4 slices enough). Then cover the ham in grated fontina cheese.
Put the drained potatoes in a large mixing bowl and add a good pinch of salt, a drizzle of olive oil and the grated Parmigiano Reggiano cheese, toss to combine.
Lay the potatoes all over the ham and cheese. Fold the edges of the pastry up and crimp it slightly (similar to a galette or crostata, see photos for reference) then brush the edges with beaten egg.
Bake the tart in the oven for 35-40 minutes until the pastry is golden brown and the potatoes cooked through. Let it sit for 5 minutes before cutting and serving.
Notes
Puff pastry - If you buy yours in a block just roll it out about 4mm (just over 1/8 inch) thick. The sheet I use is about 30x20cm (8x11.5 inches).
Preparing in advance - you can prep and assemble the tart in advance and store it in the fridge (don't brush the pastry with egg though). Remove it from the fridge 30 minutes before baking, brush with egg and bake.
Leftovers - leftovers will keep well for up to 3 days in the fridge.