This fish is marinaded and served with peppers, olives and capers.
Cut fish fillets in half, and season with salt and pepper. Place the flour on a large plate. Dredge each fillet in the flour.
Heat 2 tablespoons olive oil in a large nonstick skillet set over medium-high heat. Add half of the fillets; saute until opaque and golden brown on bottoms, 2 to 3 minutes. Turn over, and cook other sides until golden brown, 2 to 3 minutes more. Transfer fish to a deep glass or ceramic dish, in a single layer, and set aside. Wipe out skillet, add 2 more tablespoons oil; cook remaining fillets.
Wipe out skillet, add the remaining 4 tablespoons oil, and place over medium heat. Add carrots, celery, bell peppers, onions, garlic, peppercorns, chile pepper, and bay leaves. Cook 3 minutes, without browning vegetables. Add vinegar, 2 1/2 cups water, olives, and capers. Raise heat to high; bring to a boil. Remove from heat; pour mixture over fish, covering fish completely (if fish is not completely covered, add one part water to one part vinegar until covered). Let stand until cool. Cover; refrigerate at least 24 hours or up to 3 days.
When ready to serve, let escabeche stand at room temperature 30 minutes. Divide the fish and vegetables among 12 plates; garnish with lime slices and cilantro, if desired.