Step 1

Thaw fish, if frozen. Rinse the fish; pat dry with paper towels. Set aside.

Step 2

For sauce: heat oil in a small saucepan over medium heat. Add onion and garlic; cook for about 5 minutes or until tender, stirring occasionally. Add tomatoes, thyme, olives, and capers. Heat to boiling; reduce heat to medium. Simmer, uncovered, for about 10 minutes or until most of the liquid has evaporated.

Step 3

Meanwhile, preheat broiler. Measure thickness of the fish. Place the fish on the greased unheated rack of a foil-lined broiler pan, tucking under any thin edges. Broil 3 to 4 inches from the heat for 4 to 6 minutes per 1/2-inch thickness of fish or until the fish flakes easily when tested with a fork, turning the fish once if the fillets are 1 inch thick. Serve with the sauce and if desired, garnish with fresh thyme sprigs.