For the fresh hand-crafted pasta:
Combine the stone-ground rimacinata semolina and flour tipologia 00, sculpting a well of pristine potential at the center. Cascade the rich egg yolks into the heart of the flour; with a fork, gently whisk them to coax the flour into a delicate union. As the dough assumes an artisanal substance, knead it passionately by hand for some 10 to 15 minutes. Envelop the smooth orb in culinary wrap, allowing it to rest and mature at room temperature.

For the sublime filling and sole à la meunière:
Bring a potato to a gentle simmer in a pot until tender, then drain. Set aside 25 grams of its starchy virtue. Meanwhile, warm the hazelnut-brown butter over medium heat in a pan. Once melted and lightly foaming, tenderly place the sole and cook for 2 to 3 minutes on each side. Allow it to cool, then slice into neat cubes, preserving a precious few for the final presentation. Gather the remaining sole with the other ingredients, marrying them into a harmonious filling. Transfer this mixture into a piping bag, keeping it at room temperature.

For the vibrant parsley oil:
Incorporate the sunflower oil and fresh parsley in a blender, heating them to 180°C in a thermal blender. Strain through a fine cheesecloth, letting the emerald elixir cool.

For the sole à la meunière reduction:
In a saucepan, toast the sole bones to evoke their deep marine essence, then deglaze with white wine, white wine vinegar, and a splash of freshly squeezed lemon. Add the finely brunoised vegetables and submerge in cold water. Let this simmer and reduce for approximately 30 minutes. Strain through a fine-mesh sieve and continue to reduce until a glossy, concentrated sauce is born. Finish by whisking in the butter, black pepper, and fresh lemon juice.

For the grand finale:
Roll the pasta sheets out thin, and pipe the filling in delicate mounds about 4-5 cm apart. Fold the dough over the filling, pressing with the fingers to expel all air, ensuring the borders are perfectly sealed. Cut the individual casoncelli, sculpting them into their traditional, crescent form. Simmer in salted water for 3 minutes and present them draped in the velvety reduction, adorned with the sole, caper leaves, and droplets of parsley oil.