Finely grate the parmesan. Bring milk, butter and 1 pinch of salt to the boil. Add parmesan and flour. Remove the pot from the heat and knead to a smooth dough. Let dough cool down for about 10 minutes.
In the meantime, drain the tomatoes, artichokes and mozzarella and dice finely. Wash basil, shake dry. Clean the spinach, wash it and spin dry. Cut basil and 20 g spinach into fine strips.
Mix tomatoes, artichokes, mozzarella, basil and spinach, season with salt and pepper.
Roll out the dough on a floured work surface to a thickness of approx. 4 mm. Cut out 12 circles (each approx. 9 cm Ø) from the dough, but knead the rest of the dough again and roll out again. Spread the mixture in the middle of the dough circles.
Leave a small margin. Fold into crescents, press the edges together firmly. Brush dumplings with 1 tbsp. oil and turn them in breadcrumbs.
Place the dumplings on a baking tray lined with baking paper. Bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for 15-20 minutes.
In the meantime, mix vinegar and sugar in a bowl. Fold in 1 tablespoon of oil in a thin stream. Season to taste with salt and pepper. Mix the remaining spinach with the vinaigrette. Arrange with dumplings on plates.