Preheat oven to 400 degrees Fahrenheit (200 degrees Celsius).
Season fish fillets with salt and pepper on all sides.
Heat 1 tablespoon of olive oil in an oven-safe skillet over medium-high heat.
Sear the fish for 2 to 3 minutes per side until golden, then remove from the pan and set aside.
Add the remaining oil to the skillet and sauté the shaved fennel for 5 minutes until softened.
Stir in the garlic and olives, cooking for 1 minute until fragrant.
Deglaze the pan with white wine and lemon juice, scraping the bottom of the pan to release browned bits.
Place the fish fillets back on top of the fennel and olive mixture.
Transfer the skillet to the oven and roast for 8 to 10 minutes until the fish is opaque and flakes easily.
Garnish with lemon zest and chopped fennel fronds before serving.