In a 10- to 12-inch, heavy, nonstick skillet, heat the oil over medium-high heat until hot. Add the scallions and ginger and cook, stirring occasionally, until they’re just golden, with some green still visible on the scallions, 2 to 4 minutes. Remove the skillet from the heat, and with a slotted spoon, transfer the vegetables to paper towels to drain (leave the oil in the skillet). Toss the ginger and scallions lightly with salt.

Line up three wide shallow dishes. Put the flour in the first; beat the egg in the second; put the peanuts in the third. Season the tilapia fillets with salt. Dredge one fillet in the flour, shaking off the excess. Dip the fillet in the egg, then coat it with peanuts. Set the fillet on a plate and repeat with the second fillet.

Reheat the oil in the skillet over medium-high heat. Add the tilapia fillets and cook until golden on each side and the flesh is opaque and cooked through, 3 to 4 minutes on each side (reduce the heat if they brown too fast). Put the tilapia on dinner plates, sprinkle with the rice vinegar and pepper to taste, top with the frizzled vegetables, and serve immediately.

Variations

Alternative coatings: Instead of peanuts, try coating the fish with cashews or sesame seeds. Or just season the fillets with salt and pepper and sear them with no coating at all.