I need to feed visitors for a week and I want to get organised in advance. Can I freeze the Onion Tart recipe from How to Eat?
Nigella's Onion Tart With Bitter Leaves (from HOW TO EAT) is a quiche with a caramelized onion filling. The tart is at its best when freshly baked and it is possible to make the quiche in advance to various different stages and freeze it. Our preference would be to blind bake the pastry case and cook the onions until caramelized, then freeze each of these separately. Wrap the pastry case, still in its tin, tightly in a double layer of clingflilm (plastic wrap) and a layer of foil. Put the caramelized onions in an airtight container. They can both be frozen for up to 3 months. To finish the tart, thaw the onions in the fridge overnight then add them to the custard mixture. Remove the pastry case from the freezer (it can be baked from frozen) and add the filling, then bake following the instructions in the recipe.
It is also possible to assemble the tart and then freeze it and bake from frozen. To do this you need to put the assembled tart on a baking sheet and carefully open freeze until the tart is solid, making sure the baking sheet is kept flat in the freezer to stop any filling spilling out. Wrap in a double layer of clingfilm and a layer of foil and freeze for up to 3 months. Unwrap the tart and bake direct from frozen, adding 10-20 minutes to the baking time. Make sure that the tart is hot in the centre before removing it from the oven. For both of these methods we would also suggest heating a baking sheet in the oven and putting the tart on to the hot baking sheet to cook. It is also possible to freeze a baked quiche, but the pastry can be slightly soggy when the tart defrosts and the tart would still need to go into the oven to reheat.