Veracruz-Style Whitefish

Heat 2 tablespoons oil in a saucepan over medium-high heat. Add onion; cook, stirring occasionally, until softened and lightly browned, about 4 minutes. Add garlic, jalapeño, oregano, and 1/4 teaspoon each salt and black pepper. Cook, stirring frequently, until fragrant, about 30 seconds.

Pour in wine, stir, and bring to a simmer. Cook until most of the wine evaporates, about 2 minutes. Add tomatoes and their juices, olives, capers, and parsley; bring to a simmer over medium-high heat. Reduce heat to maintain a low simmer and cook, stirring occasionally, until most of the liquid is evaporated and reduced to about 2 cups, about 15 minutes. Remove from heat; cover to keep warm.

Meanwhile, heat remaining 1 tablespoon oil in a large nonstick skillet over medium-high heat. Pat fish fillets dry and sprinkle with remaining 1/4 teaspoon each salt and black pepper. Cook, turning once halfway through, until browned on both sides and fish flakes easily, 6 to 8 minutes per 1/2-inch thickness.

Serve fish with sauce and lemon wheels. Garnish with additional jalapeño slices.