Vegetable spiral tart

For the pastry:

225g plain flour

1 pinch of salt

100g butter, chilled and cubed

1 egg, lightly beaten

For the filling:

230g Mascarpone cheese

100g Cheddar cheese, finely grated

2 tbsp sun-dried tomato pesto

handful of parsley, finely chopped

½ tsp ground nutmeg

1 small yellow courgette

1 small green courgette

1 medium, long sweet potato, peeled

1 very small, long aubergine