General tips
Sous vide first, bread and fry second. The traditional method bread-and-fries raw pork, which means you're racing to crisp the panko before the inside dries out. Sous vide the pork to 140°F for 90 min first - then the fryer's only job is the crust.
Use Japanese panko, not regular breadcrumbs. Panko is light, airy, and shatters when you bite. Regular breadcrumbs make a dense, heavy coating. The texture difference is everything for tonkatsu - don't substitute.
Triple-bread for the best crust. Flour, beaten egg, panko - but do it twice for the panko layer. The double-coating gives you that dramatic, crackling crust that defines great tonkatsu. Skip the second panko pass and the crust is too thin.
Fry at 360°F for 60–90 sec. The pork is already cooked through from the bath, so you're just crisping the crust. Going longer dries out the meat. Pull as soon as the crust is golden brown and let it rest 1 min on a wire rack before slicing.
Anti-tip: don't slice tonkatsu with a serrated knife. A sharp chef's knife cuts cleanly through the crispy panko without crushing it. A serrated knife saws through and shatters the crust into the meat. Treat it like a steak, not bread.
Tender tips
Use pork loin or pork chops (boneless, 3/4-inch thick)
Japanese panko creates the crispiest coating
Pound cutlets to even thickness for uniform cooking