Finely grate the parmesan. Knead 150 g flour, half Parmesan, approx. 1/2 teaspoon salt, butter in pieces and 1 egg first with the dough hooks of the hand mixer, then quickly with your hands to a smooth short pastry.
Cover and chill for about 30 minutes.
Wash the tomatoes and cut them in half. Mix the sour cream and 3 eggs. Season with salt, pepper and nutmeg. Stir in the rest of the parmesan and basil.
Line a Tarte- or Quiche tin (approx. 26 cm Ø; alternatively a springform pan) with baking paper. Roll out the dough on a little flour (approx. 30 cm Ø) and line the tin with it, pressing the edge of the tin slightly (for the springform tin, press up only approx. 2 cm at the edge of the tin.
Prick the bottom several times with a fork.
Add the tomatoes. Pluck or cut ham into pieces and spread 2/3 in between. Pour egg cream over it. Cover with the rest of the ham. Bake in a hot oven (electric cooker: 200 °C/circulating air: 175 °C/gas: level 3) for 45-50 minutes.