How to Make It
Lay 1 piece of bread on a work surface. Place 1 fish fillet, skin side down, on top of the bread and press lightly so that the bread sticks to the fish. Trim any excess bread from around the fish. Season the fillet and the bread with salt and pepper. Repeat with the remaining rouget fillets and bread.
In a large nonstick skillet, heat 1 1/2 tablespoons of the olive oil over moderate heat. Add the fish fillets, bread side down, and cook until golden brown, about 1 minute. Carefully turn the fillets over and cook for 30 seconds. Remove from the heat and transfer the fillets to a paper towel-lined plate.
Season the arugula with the remaining 1 tablespoon of olive oil, lemon juice and salt and pepper. Mound the salad on plates and arrange 2 fish fillets, bread side up, in a crisscross pattern next to the salad. Drizzle the mosto oil and pesto around the salad and scatter the olives on top.