For the pasta dough:
Knead semolina, eggs, flour, oil, salt (1) and water (2) at the beginning with the dough hook of the mixer, then with your hands to a smooth elastic dough. Wrap in plastic wrap and refrigerate for 30 minutes.
For the filling:
Peel celery and cut into small cubes. Boil water, juice of one lemon and salt (3). Add celery cubes. Simmer for ten minutes and drain in a sieve. Grind with the hand mixer.
Fold in crema fraÂche , egg, semolina and parmesan. Season the filling with salt, pepper and freshly grated nutmeg. Roll out pasta dough thinly on a little flour using a pasta machine or pasta walker.
Cut out the quadruple mass (as indicated above)about 10 cm squares.Brush the edges with egg yolk. Form a heaping tablespoon of celery filling in the center of each square. Fold the dough into a triangle and press the edges a little smooth so that the filling does not run out.
Shape the Maultaschen into the boiling salted water and cook over low heat until just flat, about 8 minutes.
For the walnut butter:
Heat the butter. Briefly toss plucked parsley leaves in it and remove. Add coarsely chopped walnuts, maple syrup and vegetable soup to the fat form and heat for 1 minute.
Season with salt and pepper. Add parsley again. Lift the Swabian ravioli out of the water with a slotted spoon and drain. Pour the nut butter over the hot Maultaschen.