For the shortcrust pastry, sieve flour into a bowl and add 1 teaspoon salt. Add butter in flakes and 4-5 tablespoons of ice-cold water. Use the dough hooks of the mixer to make a smooth dough (takes a little longer as the dough is very crumbly at first).
Wrap in cling film and chill for about 30 minutes.
In the meantime clean, wash and drain the spinach. Peel and finely chop the onions and garlic. Heat the oil in a saucepan. Brown the onions and garlic in it. Add dripping wet spinach, cover and let it collapse for 2-3 minutes.
Season with salt and pepper. Drain and squeeze a little.
For the herb cream grate parmesan. Wash and chop the herbs. Mix crème fraîche, egg yolk, 50 g Parmesan and herbs. Season with salt and pepper.
Preheat oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer). Line a tray with baking paper. Roll out the dough into a rectangle (approx. 24 x 32 cm). Press the edge of the dough up approx. 1.5 cm.
Bake in the oven on the lowest shelf for 18-20 minutes.
Take out the cake. Spread spinach on it and crumble ricotta on it, spread herb cream on top. Sprinkle with rest of parmesan. Bake for another 18-20 minutes.