Jump to Recipe
Low-cal baked cod with tomato relish is a simple oven-baked fish dinner: cod fillets seasoned and baked until just opaque, then topped with a fresh, no-cook relish of diced tomato, basil, and lemon. One serving runs about 200 calories, so it fits easily into a lighter meal plan without tasting like diet food.
I make this on nights when I want something that feels like real food but doesn’t sit heavy. Cod cooks fast and the relish takes five minutes with a knife and a bowl.
The fish stays tender because it’s baked at a moderate temperature and pulled the second it turns opaque and flakes with a fork, at 145 F / 63 C. Overbake it by even five minutes and it turns chalky, so an instant-read thermometer helps here.
This one works for a weeknight table and for anyone watching calories without giving up flavor.
Why You’ll Love This Recipe
- Ready in under 30 minutes start to finish
- About 200 calories per serving, so it fits a lighter plate
- No-cook relish means one less pan to wash
- Cod stays flaky, not dry, when you hit the right temp
Ingredient Notes
- cod fillets: Pat them very dry before baking so they brown instead of steaming. Haddock or halibut work as a swap at the same bake time.
- olive oil: Used both for brushing the fish and for the relish. Avocado oil works fine if that’s what you’ve got.
- tomatoes: Use ripe, firm ones and drain excess juice in a sieve for 5 minutes so the relish doesn’t turn watery.
- fresh basil: Adds the bright note here. Parsley works in a pinch but tastes greener, not as sweet.
- red onion: Soak the minced onion in cold water for 5 minutes if you want to mellow the raw bite.
- capers: Give the relish a briny pop. Chopped green olives are a fine substitute if you skip capers.
- lemon: Zest before you juice it, once juiced there’s nothing left to zest.
Light Baked Cod with Fresh Tomato and Basil Relish
Ingredients
Method
- Heat the oven to 400 F / 205 C. Line a 13 x 9-inch / 33 x 23 cm sheet pan with parchment.
- Pat the cod fillets dry with paper towels and arrange on the pan with space between them.
- Brush the fillets with 1 tbsp olive oil and season with 1/4 tsp salt and the black pepper.
- Bake for 12 to 15 minutes, until the fish is opaque all the way through, flakes easily with a fork, and reads 145 F / 63 C on an instant-read thermometer.
- While the cod bakes, dice the tomatoes and let them sit in a fine-mesh sieve for 5 minutes to drain excess liquid.
- In a mixing bowl, combine the drained tomatoes, chopped basil, minced red onion, capers, and garlic.
- Add the remaining 1 tbsp olive oil, lemon juice, lemon zest, 1/4 tsp salt, and red pepper flakes if using. Toss gently and let sit 10 minutes so the flavors blend.
- Remove the cod from the oven and let it rest 2 minutes on the pan.
- Spoon the tomato relish over each fillet and serve right away, while the fish is still warm.
Notes
- Fillets vary in thickness, thinner ends cook faster, check as early as 10 minutes.
- Relish tastes better after 10 minutes resting, the flavors meld.
- Use a rimmed sheet pan so fish juices don’t run into the oven.
- Don’t skip drying the fish, wet cod won’t brown and dilutes the relish.
Tips for Success
- Pat the cod dry with paper towels before baking so it browns instead of steaming.
- Pull the fish at exactly 145 F / 63 C, cod turns chalky within a few extra minutes.
- Drain diced tomatoes in a sieve for 5 minutes so the relish doesn’t turn watery.
- Salt the diced onion and soak it in cold water for 5 minutes to mellow the bite.
- Zest the lemon before juicing it, you can’t zest a lemon once it’s been squeezed.
Variations
- Swap the capers for chopped kalamata olives for a saltier, briny relish.
- Use halibut or haddock fillets instead of cod, the same bake time and internal temp apply.
- Stir diced avocado into the relish for a creamier bite, it adds about 40 calories per serving.
Storage and Reheating
Store leftover baked cod in an airtight container in the fridge for up to 2 days. Keep the tomato relish in a separate container for up to 3 days, it holds better on its own.
To reheat, place the fish on a small baking sheet and warm in the oven at 275 F / 135 C for 8 to 10 minutes, just until heated through. Skip the microwave, it turns cod rubbery fast.
I don’t recommend freezing this dish once cooked, the texture of baked cod suffers badly after thawing. If you want to prep ahead, freeze the raw fillets and make the relish fresh the day you cook.
Serving Suggestions
Baked cod with tomato relish sits well next to something plain that soaks up the juices. Steamed white rice, a small pile of couscous, or warm crusty bread all work.
For a lighter plate, add a simple green salad with lemon vinaigrette or a pile of steamed green beans. The relish’s acidity plays well against something crisp.
A glass of dry white wine, like a Sauvignon Blanc, rounds out the meal without adding much weight to the calorie count.
FAQ
How do I know when baked cod is done?
Baked cod is done when it turns opaque all the way through and flakes easily with a fork, at an internal temperature of 145 F / 63 C. Check the thickest part of the fillet with an instant-read thermometer around the 12-minute mark. Pull it right away since cod keeps cooking a bit after it leaves the oven.
Can I use frozen cod fillets instead of fresh for this recipe?
Yes, frozen cod works if you thaw it fully and pat it very dry before baking. Extra moisture from frozen fish steams instead of browning and can water down the tomato relish. Thaw overnight in the fridge, then blot with paper towels before seasoning.
Can I make the tomato relish ahead of the baked cod?
Yes, the tomato relish holds well in the fridge for up to 2 days in an airtight container. The flavors actually deepen after a few hours as the garlic and lemon mellow into the tomatoes. Just drain off any extra liquid before spooning it over the hot fish.
What sides go well with baked cod and tomato relish?
Simple sides work best so the relish stays the star, think steamed rice, crusty bread, or a green salad. Roasted potatoes or a quick couscous also soak up the extra juices from the relish. Keep the sides light since this dish is built around low-cal ingredients.
Is baked cod with tomato relish gluten free?
Yes, this baked cod recipe is naturally gluten free since it’s just fish, olive oil, tomatoes, and fresh herbs. Double check your capers and any packaged seasoning blends if you use them, some brands add fillers. Serve it with a gluten-free side like rice to keep the whole plate safe.
Why did my tomato relish turn watery on top of the cod?
Watery relish usually means the diced tomatoes weren’t drained before mixing, or they sat too long and released their juice. Dice the tomatoes, let them sit in a sieve for 5 minutes, then toss with the other ingredients right before serving. Ripe, firm tomatoes hold their shape better than very soft ones.
