Preheat oven 350 F degrees.
Heat the olive oil in a large pan.
Add the onion and garlic.
Stir for one minute.
Add the tomatoes.
Mash the tomatoes using a potato masher. If using canned tomatoes, skip this step.
Add pickled jalapeños, oregano, bay leaf, olives, and capers.
Let everything simmer for 2 minutes.
If the sauce becomes too thick, add a splash of water to thin it out.
In a large casserole dish, add the tomato mixture and top with the fish.
Season the fish with salt and pepper.
Spoon some of the sauce over the dish.
Bake for 15 minutes or until fish is fully cooked.
Enjoy.