Knead 250 g flour, 125 g butter in pieces, 1 egg and approx. 1/2 tsp salt first with the dough hooks of the mixer, then quickly with your hands to a smooth dough. Cover and chill for about 30 minutes.
Defrost the frozen spinach and 75 ml water covered for 12-14 minutes. Stir from time to time. Then continue to simmer open for 5 minutes until all the liquid has evaporated.
Wash the tomatoes, cut them in half. Dice the gorgonzola. Mix sour cream, milk and 4 eggs. Season with salt and pepper.
Preheat oven (electric cooker: 200 °C/circulating air: 175 °C/gas: level 3). Grease 8 tartlet moulds with removable bottom (approx. 10 cm Ø). Roll out the dough onto some flour. Cut out 8 circles (approx. 12 cm Ø).
Put them in a mould. Press the edges and pierce the bottom. Spread the spinach, tomatoes and gorgonzola on top. Pour egg-cream on top.
Bake in the oven for 30-40 minutes. Sprinkle pine nuts on the tartlets about 5 minutes before the end of the baking time.