Set a large Dutch oven over medium heat. Add the olive oil and heat to shimmering, then add the onion, bell pepper, garlic and jalapeno, paprika, cayenne, cumin, and a pinch of salt. Cook, stirring occasionally, until the vegetables are tender and begin to brown, about 3 minutes.
Add tomatoes along with their juices, season with another pinch of salt and twist of black pepper, and bring to a boil. Reduce the heat to medium-low to maintain a gentle simmer, partially cover, and cook until vegetables soften and the liquid has mostly reduced, about 15 minutes.
Remove from the heat and stir in the vinegar. Season the fish on all sides with salt and pepper and partially submerge in the sauce, leaving space between the pieces. Spoon some sauce over each fillet. Transfer the pot to the oven and cook, uncovered, until the flesh of the fish turns opaque and begins to flake, about 15 minutes. Garnish with parsley and a drizzle of olive oil and serve.