How to Make It
In a large bowl, whisk the vinegar with 5 tablespoons of the olive oil. Stir in the capers, sun-dried tomatoes and basil and season the dressing with salt and pepper.
In a large nonstick skillet, heat the remaining 3 tablespoons of olive oil. Add the zucchini and cook over high heat, turning once, until golden and just tender, about 4 minutes. Season with salt and pepper. Using a slotted spoon, add the zucchini to the dressing in the large bowl, leaving the oil in the skillet.
Heat the skillet until the oil is shimmering. Season the fish with salt and pepper and add it to the skillet, skin side down. Cook the fish over high heat, turning once, until golden outside and white throughout, about 10 minutes. Transfer the fish to plates and spoon the zucchini alongside. In a small bowl, mix the black olive tapenade with the cognac and spoon over the fish. Serve right away.