Food editor Melissa Roberts learned the ins and outs of making escabeche—a Spanish dish that preserves fish by frying it, then pickling it—at Alicia Juanpere's Catacurian cooking school, near Barcelona. As the fish (in this case, robust sardines or mackerel) absorbs the vinegary dressing over time, its flavor deepens, picking up the notes of paprika and cinnamon, orange and lemon.
Cooks' notes:
•If using sardines, discard heads, then split bodies lengthwise to remove center bones and tails. Cut each fish into 2 fillets. If using mackerel, cut into 3-inch-wide pieces and remove any bones.
•Fish can be marinated up to 24 hours.