Sweet and savoury grape and shallot tart with cheese
Preheat oven to 375 degrees.
Peel and halve the shallots lengthwise. You will need enough shallots to fill an 8 or 9 inch round cake pan. (Shallots vary in size, so it's difficult to predict exactly how many you will need). Arrange the shallots cut-side down as tightly as possible in the pan so that you will know approximately how many you will need for the recipe. Remove the shallots from the pan and place them in a bowl and set aside for later. (The shallots will shrink a little as they cook, so prep a couple of extra shallots and add them to the bowl).
Generously butter the bottom of the cake pan with 2 tbsp of room temperature butter and then put the pan in the fridge to set the butter.
Place a large non-stick frying pan over medium heat. Add the olive oil. When the oil is hot, add the shallots, rounded-side down. Season with salt and pepper. Saute for a minute and then gently flip the shallots over. Cook the shallots cut-side down for two minutes or until the shallots are golden brown. Then turn off the heat.
Add 1/2 cup water and 3 tbsp balsamic vinegar to the pan. Then add one cup of the halved grapes to the pan in between and around the shallots. Turn the heat to high. When the liquid comes to a boil, turn the heat down to medium. Braise the shallots until most of the liquid has reduced. Allow everything to cool a little before transferring the shallots and the grapes to the buttered cake pan.
While the shallots are cooling, roll out the puff pastry and cut out a circle that is about an inch larger than the cake pan. Prick the pastry all over with a fork.
Remove the buttered pan from the fridge. Use a spatula to place the carmelized shallots as tightly as possible in the pan, cut-side down. Start in the center and work your way to the edges. Then add the caramelized grapes in between the shallots. (Don't worry if the shallots have shrunk and don't completely fill the pan to the edges. The pastry will fill the gap around the edges).
Pour the melted butter on top. Then add the grated cheese. Drape the pastry over everything and tuck in the edges.
Bake at 375 degrees for 40 to 45 minutes or until the pastry is golden to medium brown. Remove from the oven and let cool for 5 minutes to allow the caramel/syrup to thicken a little.
Shake the cake pan from side to side to release the tart. Put a serving plate on top of the cake pan and carefully and quickly flip it over. (Be careful - the caramel/syrup is very hot). Slowly lift off the cake pan. Hopefully the tart comes out intact, but don't worry if some of the toppings remain in the pan. You can easily transfer any shallots that didn't make it onto the tart with a spatula. It will still look amazing.