Chop the butter and add to the flour. Use your fingertips to mix it together till it is like breadcrumbs. Add the sugar and the egg and mix together. Form the mixture into a ball, wrap in clingfilm and put in the fridge for half an hour.
Line a flan tin with baking paper. I used a case about 20cm across but a larger one would have been better as I had quite a bit of pastry left over and the filling was very full.
When the pastry has rested. Take it out of the fridge. Flour the work surface and roll it out till it is about 3mm thick. Put it in the flan case. Add baking beans and bake for 10 minutes at about 200°c. Remove the beans, prick the bottom of the pastry a few times with a fork and return to the oven for another ten minutes.
Prepare the frangipane by creaming the butter and sugar together. Then beat in the eggs. Then the almonds and flour. Mix until all the almonds and flour are combined. Add to the pastry case.
Slice a nectarine and arrange the slices on top of the tart. Return to the oven. Timing will depend on the thickness of the tart. Mine needed 45 minutes but if you use a larger dish it will be ready much quicker. I would advise checking after 30 minutes.
Nutritional information is approximate and a guideline only.