Soak the buns. Peel onions, chop 2 pieces finely. Cut remaining onion into rings. Wash and chop parsley. Mix the ground pork fat, squeezed out roll, egg, half of the finely diced onion, parsley, Italian herbs and mustard.
Season with salt and pepper. Shape into about 8 meatballs with wet hands. Put the noodles in boiling salted water and cook for 8-10 minutes. Fry the meatballs in hot oil while turning for about 8 minutes. Add onion rings to the frying fat and brown until crispy.
In the meantime drain the mushrooms. (Clean and wash the fresh mushrooms.) Melt the fat and fry the remaining chopped onion in it. Add the mushrooms and fry well. Deglaze with cream and 250 ml water, boil down a little.
Season with salt, pepper and stock. Add sauce thickener, (for fresh mushrooms dust the fried mushrooms with flour) season again. Serve meatballs and creamed mushrooms garnished with parsley and tomato.
Cut 80 g butter into cubes. Wash the orange hot, grate dry and grate about half of the peel thinly. Knead 150 g flour, 80 g sugar, egg yolk, 1 pinch of salt, 1-2 tablespoons cold water, half of the orange peel and butter cubes to a smooth dough. Roll out the dough on a floured work surface to a circle (approx. 24 cm Ø). Line a greased springform pan (18 cm Ø) with the dough. Cover the mould with foil and chill for about 30 minutes.