The Japanese usually keep the heads and tails of smelts intact, just gutting the belly cavity, but you may be happier removing the heads and tails, along with the guts. Rinse the cleaned fish thoroughly in salted water. (The water should taste briny, like the ocean.) Gently pat the fish dry, inside and out, then dust them in the cornstarch.
In a wok or deep-fat fryer, heat the oil to ap