Put the flour and 1/2 teaspoon salt in a bowl and press a depression into it. Add 3 eggs, 3 tablespoons cold water and 2 tablespoons oil. Knead first with the dough hooks of the hand mixer, then with your hands to a smooth dough. Wrap in foil and let rest for about 45 minutes
Meanwhile wash the asparagus, cut off the woody ends. Halve the asparagus. Put the upper halves aside. Cut lower halves into very fine slices. Put asparagus slices in boiling salted water and cook for about 2 minutes. Pour into a sieve and drain well
Separate 1 egg. Whisk the egg whites with a fork. Stir cream cheese and egg yolk until smooth. Season with salt and pepper. Carefully mix in the asparagus slices. Halve the noodle dough. Wrap one half well in foil again. Roll out one half thinly (45 x 45 cm) on a floured work surface. Mark half of the pasta sheet. Spread 15 small heaps (3 x 5) of asparagus filling with a tablespoon at evenly spaced intervals on one half. Brush the gaps with egg white
Fold over the dough sheet. Press the gaps very firmly. Cut squares with a dough wheel. Process the second half of the dough and the rest of the filling in the same way
Wash the shrimps and pat them dry. Peel and finely chop the onion. Cut the upper asparagus halves into large pieces. Place two portions of Maultaschen in plenty of boiling salted water and cook for 8-10 minutes. Drain and keep warm
Heat 2 tablespoons of oil in a frying pan. Sauté the prawns in it while turning. Add onion and asparagus and fry for approx. 3 minutes, turning. Season with salt and pepper. Heat butter in a small pot. Arrange Maultaschen and prawns in a bowl. Drizzle with butter
Waiting time approx. 25 minutes