This oven-baked fish with tomatoes and olives is my go-to when I want a healthy dinner that tastes like you ordered it from a coastal restaurant—bright tomatoes, briny olives, a little garlic, and tender, flaky fish.
Why you’ll love this recipe
- Fast: ready in about 25 minutes, start to finish.
- Easy cleanup: everything bakes in one dish.
- Flexible: works with most mild white fish (fresh or thawed).
- Big flavor: tomatoes + olives + lemon make a quick pan sauce right in the oven.
Ingredients
- 1 1/2 lb mild white fish fillets (cod, haddock, tilapia, pollock, halibut, or mahi-mahi)
- 2 cups cherry tomatoes, halved (or 1 (14.5 oz) can diced tomatoes, drained)
- 1/2 cup pitted olives (Kalamata or mixed), halved
- 3 tbsp extra-virgin olive oil, plus more for drizzling
- 3 cloves garlic, thinly sliced (or minced)
- 1 tsp dried oregano (or 1 tbsp chopped fresh oregano)
- 1/2 tsp kosher salt, plus more to taste
- 1/4 tsp black pepper
- Pinch red pepper flakes (optional)
- 1 tbsp capers, drained (optional)
- 1 lemon (zest + 1–2 tbsp juice)
- 2 tbsp chopped fresh parsley or basil, for finishing
Best fish to use
This recipe is ideal for flaky, mild fillets that bake quickly. Cod and haddock are classic, but tilapia and pollock are budget-friendly, and halibut or mahi-mahi feel a little more special. If your fillets are very thin, start checking for doneness a few minutes early.
How to make oven-baked fish with tomatoes and olives
- Preheat the oven to 425°F. Lightly oil a 9×13-inch baking dish (or similar).
- Add the tomatoes, olives, olive oil, garlic, oregano, salt, pepper, and red pepper flakes (if using) to the dish. Toss to combine and spread into an even layer.
- Roast the tomato mixture for 10 minutes to get it sizzling and juicy.
- Nestle the fish fillets into the tomatoes and olives. Drizzle with a little olive oil and sprinkle with lemon zest.
- Bake 8–12 minutes, depending on thickness, until the fish flakes easily and is opaque. (For food safety, fish should reach 145°F in the thickest part.)
- Finish with a squeeze of lemon juice and a shower of parsley or basil. Spoon the tomato-olive sauce over the fish before serving.
Tips for perfect, flaky fish
- Don’t overbake: pull the fish as soon as it flakes and turns opaque.
- Start the sauce first: giving the tomatoes a head start builds a better pan sauce.
- Use even thickness: if one fillet is much thicker, place it in the center of the dish where it’s hottest.
- If using frozen fish: thaw overnight in the fridge, then pat dry well to avoid watering down the sauce.
What to serve with it
- Cooked orzo, couscous, or rice to soak up the sauce
- Crusty bread and a simple green salad
- Roasted potatoes or cauliflower
- Steamed green beans or sautéed spinach
Storage and reheating
- Refrigerate: Store leftovers in an airtight container for up to 2 days.
- Reheat: Warm gently in a 300°F oven until just heated through, or microwave in short bursts. (Fish dries out fast, so go low and slow.)
- Freeze: Not ideal for best texture, but you can freeze up to 1 month; thaw in the fridge and reheat gently.
Variations
- Add thinly sliced fennel or red onion to the tomato mixture.
- Swap oregano for Italian seasoning or thyme.
- Add a splash of white wine to the tomatoes before roasting.
- Make it heartier with a handful of baby spinach stirred in right after baking.
