Clean and devein the shrimp, then season with salt and white pepper
Set up a breading station with flour, beaten eggs, and panko breadcrumbs
Coat each shrimp in flour, then dip in beaten egg, and coat with panko breadcrumbs
Fry the breaded shrimp until crispy and golden
Caramelize the sliced shallot in butter until golden and fragrant
Mix Kewpie mayo, sour cream, caramelized shallot, chili crisp, white pepper powder, rice vinegar, soy sauce, and sesame oil to make the sauce
Season the sauce with salt to taste
Combine sliced cucumber and Fresno pepper in a bowl
Mix rice vinegar, water, and sugar to create the pickling liquid
Pour the pickling liquid over the cucumber and pepper mixture and let sit
Assemble the sandwich with fried shrimp katsu, shallot sauce, and spicy pickles
