Rinse salmon fillet, dab dry and cut into coarse cubes. Wash and halve the tomatoes. Dice mozzarella finely. For the glaze, stir cream cheese, eggs and starch until smooth. Season well with salt and pepper.
Grease a baking tray (30 cm Ø; round baking tin with sloping rim) and dust with flour. Preheat the oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer). Unroll puff pastry and remove from paper.
Place the dough sheets on top of each other and fold them up once. Roll out the dough square on some flour and roll it out round (approx. 38 cm Ø). Line a springboard with the dough, press the dough on the bottom and sides and let it hang over the edge of the mould.
Sprinkle the base with breadcrumbs.
Spread the salmon, tomatoes and mozzarella on the bottom. Pour over the top. Fold the protruding edge inwards if necessary. Bake in a hot oven on the lowest shelf - this way the base will be crispy - for about 15 minutes.
Switch the temperature down (electric oven: 175 °C/circulating air: 150 °C/gas: see manufacturer) and continue baking for approx. 50 minutes. Eat hot or cold as you like.