How to Make It
Line a 9-by-13-inch roasting pan with foil; spread with the applewood chips. Cover loosely with foil and char over moderately low heat until heavy smoke gives way to light wisps, about 7 minutes.
Place the trout fillets skin side down on an oiled rack set 2 inches above the chips.
Season the fish with salt and cover with foil; smoke over low heat until just cooked, 5 minutes. Remove the skins, transfer the fish fillets to plates and serve.