Step 1

Preheat oven to 450°F. Place lemon slices in a single layer on a large roasting or baking pan. Lay thyme sprigs over lemons and sprinkle with olives.

Step 2

Halve each potato, place in a large bowl, and fill with water to cover. Microwave until potatoes are easily pierced with a knife, about 10 minutes. Drain potatoes and scatter around edge of pan.

Step 3

Place fillets on lemon and drizzle olive oil over fish and potatoes. Season with salt and pepper. Transfer to oven, reduce temperature to 325°F, and roast until fish is cooked through, about 25 minutes. Serve fish with potatoes and olives.