For the dough, mix flour, baking powder, 1 level teaspoon salt, pepper and nutmeg. Add the quark, cheese, egg and 3 tbsp. oil and knead to a smooth dough with the dough hooks of the hand mixer. Wrap in foil and let rest
Fennel clean, wash, halve and cut out the hard stalk. Cut the flesh into strips. Heat 4 tablespoons of oil in a frying pan. Cover the fennel strips and steam for about 20 minutes. Season fennel with salt, pepper and sugar, pour into a bowl and let cool. Drain tuna and anchovy fillets
Grease a tart mould with removable base (approx. 20 cm Ø) and dust with flour. Roll out the dough thinly (approx. 25 cm Ø) on a floured work surface and line the mould with it. Prick the base several times with a fork. Pick up the tuna and spread it on the bottom of the tart. Place the fennel on top and cover with anchovy fillets in strips. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for approx. 25 minutes