Preparation
First, prepare the filling. Slice the onions and heat them in oil until they become translucent. Add 2 tablespoons of sugar and continue to heat until the sugar has melted and the onions turn caramelized brown. Stir in the spinach leaves and let the mixture cool down
Prepare the pastry base. Mix the salt into the flour, add the cold butter pieces, and blend until you have a uniform crumbly mixture. Gradually add cold water and knead into a dough. Press the dough into the bottom of the tart pan using floured hands.
Chop the smoked chicken and sprinkle it over the dough. Pour the onion and spinach mixture on top. Beat the eggs and mix in the mayonnaise and milk. Season with salt and pepper. Pour the mixture over the filling and bake in a 180-degree Celsius oven for 30 minutes.
