Pat the White Fish Fillet dry and season both sides with the juice of one Lime, a generous pinch of Salt and freshly ground Black Pepper. Let rest while you prepare the sauce.
Heat 2 tablespoons of Olive Oil in a large skillet over medium-high heat. Sear the fish 1–2 minutes per side just to brown; transfer to a plate and set aside (it will finish cooking in the sauce).
Reduce the heat to medium and add another tablespoon of Olive Oil if needed. Sauté the chopped White Onion until translucent, then add minced Garlic and cook until fragrant, about 30 seconds.
Stir in chopped Tomato, a Bay Leaf and a pinch of Dried Mexican Oregano. Cook the mixture until the tomatoes break down and become saucy, about 6–8 minutes.
Add sliced Pickled Jalapeño (to taste) and a splash of the Pickled Jalapeño Brine along with about 1/4 cup of Dry White Wine to deglaze the pan; simmer for 2–3 minutes to meld the flavors.
Stir in the Pitted Green Olives and Capers, then taste and adjust seasoning with more Salt and Black Pepper as needed.
Return the seared fish to the skillet, nestling it into the sauce. Spoon sauce over the fillets, cover, and simmer gently until the fish is cooked through and flakes easily, about 6–8 minutes depending on thickness.
Remove from heat, discard the Bay Leaf, sprinkle with chopped Flat-Leaf Parsley and finish with an extra squeeze of Lime. Serve immediately with rice, crusty bread or warm tortillas to soak up the sauce.
