Defrost the spinach. Peel onion and garlic and dice finely. Clean, wash and finely dice the peppers. Heat the oil in a large pan. Sauté onion, garlic and paprika in it. Add the spinach.
Stir in the ricotta, season with salt, pepper and nutmeg. Let it cool down.
For the short pastry, put flour, 2 eggs, 2 teaspoons salt, sugar, 4 tablespoons cold water and butter in flakes in a mixing bowl. Knead first with the dough hooks of the hand mixer, then with your hands to a smooth dough.
Wrap in foil and chill for about 30 minutes.
Roll out half of the dough on a floured work surface until round (approx. 30 cm Ø), if necessary cut a little bit with a knife. Place on a baking tray lined with baking paper. Spread approx. 3/4 of the spinach mixture as an outer ring on the dough circle, leaving a distance of approx. 3 cm from the edge of the dough.
Pour the rest of the spinach mixture into the middle of the dough circle, leaving a gap of approx. 3 cm. Separate 1 egg. Spread the edge and the space between the dough with egg white. Roll out the other half of the dough round (approx. 32 cm Ø).
Carefully place on the spinach dough circle. Press down the outer edge. Slightly press a bowl (approx. 10 cm Ø) into the middle.
Press the edge with a fork and score it. Cut the outer edge at approx. 5 cm intervals in a trapezoidal shape. There should be a distance of approx. 3 cm to the bowl rim. Remove the bowl and press the space between the two edges with your thumb.
Turn trapezoidal dough pieces by approx. 90° so that the filling faces upwards.
Whisk the egg yolk and 1 tablespoon of water, brush the dough with it. Sprinkle inner circle with seeds. Bake in the preheated oven (electric oven: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) on the lower rack for about 40 minutes.