1 cup yellow cornmeal
4 (8-oz) trout fillets such as lake (preferably) or rainbow trout
3 tablespoons olive oil
1 1/4 lb baby spinach, any coarse stems discarded
1/2 stick (1/4 cup) unsalted butter
1/4 cup pine nuts, toasted
Accompaniment: Lemon wedges
Put cornmeal on a large plate. Lightly pat fish with paper towels and season with salt and pepper, then coat fillet well with cornmeal. Heat 1 tablespoon oil in a large heavy skillet over moderately high heat until hot but not smoking, then saute one third of spinach, stirring constantly, until slightly wilted but still bright green, 15 to 30 seconds. Transfer cooked spinach to a bowl. Saute remaining spinach with remaining oil in same manner. Season with salt. Wipe skillet with a paper towel, then heat 2 tablespoons butter over moderate heat until foam subsides. Increase heat to moderately high and saute two fillets, skin sides down first, turning once, until golden brown and just cooked through, about 4 minutes (do not clean skillet). Repeat with remaining butter and fillets, then reserve browned butter in skillet. Divide spinach among plates and top with pine nuts and fish, then drizzle fish with browned butter.