Heat the oven to 200°C (180°C in a fan oven), 400°F, gas 6.
Roll out the pastry thinly and cut out eight 10 cm ⌀circles and eight 12 cm ⌀circles. Place the larger circles in the pie dishes and pull the edge up.
Mix together the tomatoes, garlic, crab meat, shrimps, parsley, eggs and the breadcrumbs and season with salt and ground black pepper.
Transfer the mixture to the pie dishes and place a lid on each one. Press the edges together firmly and create a pattern around the edge using a fork. Mix the egg yolk with 2 tbsp water and brush onto the pies.