Heat one very large or two medium sized sauté pans over medium high heat for a minute then add olive oil. When hot, add fish filets seasoned with salt and pepper, flesh side down and turn the heat to very high. Sear the filets until golden brown and flip to sear on the other side. Remove filets from pan and reserve on a rack over a plate to catch juices.
Return the pan (or pans) to the heat, add onions, and cook, stirring often over high heat for 2 to 3 minutes. Add the garlic, jalapeño slices, lime wedges, tomatoes, oregano, and olives and sauté briskly for 1 minute more. Add white wine and reduce by half. Add fish stock and bring to a boil, reduce to a simmer, and return fish filets along with the juices to pan to finish cooking, covered, about 1 to 3 minutes depending upon the thickness of filets. Taste broth and adjust seasoning, then serve immediately in soup plates with a generous puddle of broth.