Place the vegetables in a hot pan without defrosting them, fry over a high heat for approx. 4 minutes, stirring continuously. Stir-fry for a further 4 minutes at medium heat, stirring several times.
Meanwhile roll out the dough, cut it into quarters with a sharp knife and sprinkle each piece of dough with breadcrumbs in the middle. Separate the egg, beat the egg white with a fork and brush the edges of the dough with it.
Place the pan-fried vegetables in the middle of the four dough pieces, fold them up and press them down. Place the dough pockets on a baking tray lined with baking paper and bake in a preheated oven (electric range: 225 ° C/ gas: level 4) for about 15 minutes.
Whisk the egg yolk and cream, spread the dumplings 5 minutes before the end of the baking time and sprinkle with sesame seeds. In the meantime clean, wash and slice the tomatoes. Clean, wash and drain the salad well.
Mix vinegar, salt, pepper and sugar. Whip the oil into the mixture. Mix tomatoes, olives and salad. Arrange lettuce on plates, drizzle with some vinaigrette and place dumplings on top. Serve garnished with parsley as desired.