Heat 1 tablespoon of the oil in a large nonstick skillet over medium-high heat.
Season the fish with ¼ teaspoon each salt and pepper and cook until opaque throughout, 4 to 5 minutes per side.
Meanwhile, heat the remaining tablespoon of oil in a second large skillet over medium-high heat.
Cook the peppers and onion, stirring often, until tender, 8 to 10 minutes.
Stir the olives, parsley, lime juice, and ¼ teaspoon each salt and pepper into the vegetables. Serve with the fish.