Heat the olive oil over medium-high heat in a large heavy skillet. Add the onion and cook for 4-5 minutes until beginning to soften. Add the garlic, oregano, thyme, and red pepper flakes. Cook for 30-60 seconds until fragrant.
Nestle the fish into the tomato sauce. Do not cover the fish with the sauce. Option 1: Place in the oven covered and cook for 8-12 minutes until the fish is flaky and cooked through. Option 2: This fish can also be cooked right on the stovetop. Simply cover the fish and simmer for 8-12 minutes until the fish is cooked through and flaky.