Rub butter into flour (or do in a food processor until crumbly), add egg yolk and enough lemon juice to mix to a firm dough. Cover in plastic wrap and put in the fridge for 30 minutes. Roll out to fit a 23 cm flan tin or pie dish, line dish and trim edges. Put layer of greaseproof paper over the pastry, fill with some rice and bake at about 400° for about 10 minutes. Remove paper and rice, bake for another 5 minutes.

Put the tomatoes in a bowl, cover with boiling water and stand for a few minutes. Remove the tomatoes, peel and then cut into 1 cm slices. Wash and slice the leek finely. Melt butter for filling in a frypan, add the leek and cook until tender. Beat the eggs in a bowl, add the cream, cheese and leek, stir to combine, and pour into the pastry case.

Combine the basil and parsley in a bowl, roll the tomatoes slices in the herbs to coats them well with herb, and place the slices on the top of the filling. Sprinkle with a little salt, plenty of black pepper and the Parmesan cheese. Bake at 350° for about 30 minutes