Salt, egg yolks, flour and a few drops of cold water to prepare a firm, smooth dough. Wrap in plastic wrap and rest for 1 hour.
Mix ricotta cheese with trout caviar, egg yolk and juice of one lemon and season with salt and pepper.
Rinse parsley and pluck leaves from stems.
Roll out the pasta dough thinly and place the parsley leaves between two layers. Roll out the dough again. On one half of the dough form nut-sized heaps of trout ricotta, brush the edges with egg white. Cover with a 2nd layer of dough and press the edges smooth. Cut out round ravioli from dough.
Blanch (scald) tomatoes with boiling hot water, rinse, skin, seed and cut into cubes.
Cook the ravioli in enough boiling hot salted water for 5 min.
Rinse and chop the spring onions. Heat butter, sauté diced tomatoes and spring onions in it. Wash the lemon, wipe it dry and separate the peel from half of the fruit with a zester. Add to the tomato sauce form and season the whole with salt and pepper.
Drain the ravioli well and serve with the tomato-lemon sauce.
Our tip: As an alternative to fresh herbs, you can also use frozen ones – they also stand out for their fresh taste!