2 tablespoons olive oil + 1 tablespoon oil to cook the fish
1 medium yellow onion, peeled and sliced crosswise
3 to 4 large cloves garlic, peeled and thinly sliced
1 (28-ounce) can high-quality diced tomatoes, drained (2 cups)
½ cup thinly sliced Spanish green olives with pimentos
¼ cup small capers
1½ tablespoons dried oregano, preferably Mexican
1 teaspoon ground cinnamon
3 to 4 whole cloves
2 bay leaves
¼ cup dry white wine
2 to 3 teaspoons freshly squeezed lime juice
Salt and freshly ground black pepper
4 (6-ounce) firm white fish fillets, such as hake, haddock, or tilapia, rinsed and blotted dry
Sliced pickled jalapeños, for garnish
Preheat your oven to 400°F. In a large non-reactive skillet, heat the 2 tablespoons of olive oil over medium-high heat until hot. Add the onions, reduce the heat to medium, and sauté until translucent, stirring occasionally; add the garlic and cook for 30 seconds. Stir in the tomatoes, olives, capers, oregano, cinnamon, cloves, and bay leaves. Stir in the wine and bring to a boil, then reduce the heat and simmer for 15 minutes, stirring occasionally. Stir in the lime juice and salt and pepper to taste, and cook 30 seconds longer. Remove the bay leaves.
Meanwhile, heat a cast iron skillet large enough to comfortably hold the fish in a single layer over high heat until hot. Brush the skillet with the remaining oil. After seasoning the fish fillets on both sides with salt and pepper, lay them in the pan and brown them on both sides, about 3 minutes per side. Then transfer the skillet to the oven to bake until the fillets are done, 4 to 5 minutes, depending on the thickness of the fish. Garnish each fillet with a few sliced jalapeños, if desired, and spoon the sauce around the fish.