In the US, we're obsessed with keeping our crisply fried foods as crisp as possible. What's the point of frying a chicken cutlet or battering an onion ring if it's just gonna get soggy again, right?
This is not the case in Japan, where there are tons of dishes that start with crisply frying food, only to then douse it in a soup or sauce that kills its crispness. Dishes like agedashi tofu (tofu that's fried until crackling like an eggshell, then coated in dashi stock so it turns slippery and tender); or tempura udon (crisply fried tempura shrimp, served all soggy-like in udon broth); or chazuke (hot tea poured over crisply fried seafood and vegetables until they're limp and saturated).
I admit: The idea doesn't sound so great when you describe it like that, but these dishes all end up with really unique textures and flavors. Frying drives off excess moisture from batters and breadings, which leaves behind plenty of open spaces to absorb flavorful liquids. Mexican chiles rellenos use a similar concept. Not sold? Well, an easy way to dip your feet into the world of fried-then-soaked foods is katsudon, a dish made with leftover chicken katsu or pork tonkatsu simmered with eggs in a soy-dashi broth, then served over a bowl of rice.
There's no easy way to reheat katsu so it comes out crisp and juicy, so what harm can it do to give this version, which embraces the sogginess of leftovers, a shot?
The process for making it is almost identical to that of oyakodon, a similar rice bowl topped with simmered fresh chicken and egg.
You start by combining dashi, soy sauce, mirin, sake, and sugar in a shallow pan and bringing it to a simmer. Traditionally, you'd use a specialized pan called a donburi pan, which has a lid with a hole in the center to allow steam to escape, but any small skillet will do.
Once the broth is at a simmer, add your katsu (leftover or otherwise), sliced into chopstick-sized pieces, and simmer it until it's warmed through. If you like, you can also add a thinly sliced onion to the broth before adding the katsu. Finally, drizzle the whole thing with a couple beaten eggs—I like to beat scallions in with my eggs—cover it, and let it steam just until the egg is cooked through. This takes just about a minute for very loose eggs (the way I like it), or a couple of minutes for medium eggs.
Once the eggs are set the way you like them, just slide the whole thing out on top of a bowl of rice. The sweet-and-savory broth soaks into the rice, while the eggs and totally-soggy-but-delicious katsu steam away on top. For my money, there's no better way to reheat and serve leftover chicken or pork cutlets.
Embrace the sogginess, and let the flavor wash over you.