Preheat the oven to 375 degrees F.

Lay the pastry into a 9 inch tart or skillet.

Bake in the oven for 10 minutes.

In a bowl, whisk the egg and the sugar together until light, about 5 minutes of fast hand whisking.

Add the lemon juice, melted butter and zest to the bowl and gently combine.

Pour the mixture into the par-baked crust and bake for a further 25-30 minutes or until the center is no longer jiggling and is a golden brown color.

Let the tart rest until cool and then place in the refrigerator before slicing.