Keep in mind there is no reason you need to use carp here; it's just that carp is traditional. Any small fish that can fit in a wok will do: Rock cod, bluegills, smallmouth bass, white bass, black seabass, porgies, spot, croaker -- you get the point. Any fish that's a little too small to properly fillet works.
2whole carp or other pan-sized fish,scaled and gutted
MARINADE
3chopped green onions
A 1-inch piece of finely chopped,peeled ginger
2tablespoonsChinese cooking wine,or Japanese Mirin
2tablespoonssoy sauce
1teaspoonfreshly ground black pepper
1chopped hot chile
1teaspoonSichuan peppercorns(optional)
VEGETABLES
A 3-inch piece of peeled ginger
1/2medium onion
5clovesgarlic
1/2finely chopped habanero chileor 1-2 Thai chiles or 1 serrano
SAUCE
5tablespoonswater
5tablespoonstomato sauce or ketchup
3tablespoonssugar
2tablespoonsChinese cooking wine,or Japanese Mirin
2tablespoonssoy sauce
2teaspoonscorn starch
GARNISH, ETC.
2tablespoonsfinely chopped cilantro
2finely chopped green onions or chives
2-4cupspeanut or vegetable oil
1cuprice flour,potato flour or regular flour for dredging
1/2cupchopped, pickled chiles(optional)
Instructions
Prepare the fish. Cut off any spines of each fish with kitchen shears or scissors. Remove the gills of the fish if they are still attached by cutting them out with the kitchen shears. Make vertical slices along each side of the fish evenly spaced along its length, about 1/2 to 1/4 inch apart from each other -- this is very important, because carp have an extra set of bones you need to cut. Doing this shortens the bones and opens them up to the hot oil, which softens them enough to eat. Rinse the fish under cold water and pat dry.
Marinate the fish. Put the 3 chopped green onions, chile, the 1-inch piece of finely chopped ginger, the Chinese cooking wine, soy sauce and the black pepper into a blender and buzz to combine. Pour the mixture into a glass or plastic container, or a Ziploc bag. Add the Sichuan peppercorns, if using. Place the fish in the container and make sure the marinade surrounds the fish. Let this sit in the fridge for 30 minutes to 3 hours.
When you are ready to cook the fish, take it out of the fridge to come to room temperature.
Prepare the vegetables. Julienne the 3-inch piece of ginger. Keep in mind 3 inches is a guideline, so the ginger can be a bit larger or smaller. Cut the ginger into a rectangle, then slice it into thin rectangles about 1/8 inch thick. Then slice these thin rectangles into very thin strips -- as thin as you can make them.
Slice the 1/2 onion into very thin half-moons. Slice the garlic cloves as thinly as you can along the long side of the clove to make long pieces.
Pour the oil into a wok and turn the heat on to medium-high. If you do not have a wok, use the largest, deepest skillet you have. A wok really matters here, though, as its shape prevents the tail fin from burning to charcoal.
Meanwhile, make the sauce. Mix the tomato sauce -- I use pureed tomatoes -- sugar, soy sauce, Chinese cooking wine, water and corn starch and stir vigorously to combine. Set it aside.
Check the oil temperature. You want it to be about 325°F. If you do not have a thermometer (you should buy one!) the oil is ready when a drop of flour tossed into the oil sizzles immediately. Fry the fish. Remove the carp from the marinade and dredge in flour. Shake off excess, and when the oil is at hot, slip the fish one at a time into the oil. You are probably going to have to cook one fish at time. If so, turn the oven on to "warm."
Fry the fish for at least 5 minutes per side. You want it to be golden brown. I will fry a 1-pound fish for 8 minutes on the first side, 5 minutes on the other side. Larger fish will need more time. When the first fish is done, remove it to a plate and put the plate in the warm oven. Fry the second fish the same way as the first.
Finish the dish. When the fish are done, ladle out all but about 1/4 cup of oil. Toss in the slivered ginger, the onion, the chiles and the slivered garlic and stir-fry over high heat for 2 minutes. Add the sweet-and-sour sauce and stir well to combine. Bring this to a rapid boil and stir well. Cook for 2 minutes.
To serve, pour some sauce on a plate, place the fish on top of it and garnish with the finely chopped chives and cilantro. This dish goes best with simple steamed white rice.