Sometimes, the best meals come from the simplest ingredients. Baked Fish with Tomato and Onion is a perfect example – a rustic, Mediterranean-style dish that’s both healthy and full of flavor. It’s the kind of recipe that feels elegant enough for a dinner party, yet easy enough for a quick weeknight meal.
At the heart of the dish is a fresh, mild white fish – something like cod, haddock, or sea bass works beautifully. Baking the fish allows it to stay moist and tender, gently absorbing the flavors of the ingredients surrounding it. Instead of heavy sauces or spices, this dish relies on the natural sweetness of onions and the bright acidity of tomatoes to bring everything to life.
As the fish bakes, the sliced onions soften and caramelize slightly, while the tomatoes break down just enough to create a rustic, savory sauce. A drizzle of olive oil, a sprinkle of salt and pepper, and a touch of garlic or fresh herbs like parsley or oregano round out the flavor. The result is a comforting dish that’s light, fresh, and deeply satisfying.
This baked fish is incredibly versatile. It can be served over rice, alongside roasted potatoes, or with a simple green salad. A squeeze of fresh lemon before serving enhances the natural brightness of the tomatoes and ties everything together beautifully.
What’s especially great about Baked Fish with Tomato and Onion is how effortless it is to prepare. It requires minimal prep and only one dish, making cleanup a breeze. Yet, the flavors are anything but basic – it’s one of those recipes that tastes like you spent hours in the kitchen.
Whether you’re cooking for family, hosting friends, or just treating yourself to a wholesome dinner, this dish is a go-to. It’s comfort food with a healthy twist – light, nourishing, and packed with Mediterranean charm.

Ingredients
- 4 fillets fish fillets
- 2 Tomatoes chopped
- 1 onion sliced
- 2 cloves garlic minced
- 2 tbsp olive oil
- 1 tbsp lemon juice
- 1 tsp dried oregano
- Salt and pepper to taste
Instructions
- Preheat the oven to 180°C (350°F).
- Place the fish fillets in a baking dish.
- In a bowl, mix together the chopped tomatoes, sliced onion, minced garlic, olive oil, lemon juice, dried oregano, salt, and pepper.
- Pour the tomato and onion mixture over the fish fillets and spread it evenly.
- Bake in the preheated oven for 25 minutes, or until the fish is cooked through and flakes easily with a fork.
- Serve the baked fish with tomato and onion sauce hot, garnished with fresh herbs if desired.
This recipe is so easy! I loved how the tomatoes made the fish super juicy. 5 stars!
Can I use frozen fish instead? Just wondering if that will mess it up.
Didn’t turn out well for me. Fish was dry and the tomatoes didn’t help. Disappointed.
Sorry to hear that! Maybe it was overcooked? Fish can dry out pretty quick. I usually marinate mine before baking.
So delish! I added some chili flakes for extra kick and it was amazing. Definitely making again!
This was delicious! The flavors blended so well! Will definitely make again.
This recipe is a game changer! The fish turned out so tender and flavorful. Can’t wait to make it again!
Super easy and quick! Perfect for weekdays!
Not my thing. Fish should be grilled, not baked! 😒
I subbed lemon with lime, still tasted great! Cooking is all about experimentation! 🥙
Never thought to bake fish with tomatoes! Wow, so delicious!!
Easiest fish recipe! I added some cheese on top, delicious!
I thought it was okay, but my husband didn’t like it at all. He said too much onion.
This is such a simple and delicious recipe! My family loved it!
Tasty! But I forgot to add garlic and it was still alright.
I tried this but it didn’t turn out like the picture. My fish was dry, maybe I overcooked it?
It sounds like you might have cooked it a little too long. I usually check my fish at 20 minutes. Give it another try!
Sounds nice but do i really have to preheat the oven? Seems too much work.
Preheating is important! It helps the fish cook evenly. Just take a few minutes to do it!
Honestly, I never preheat and it turns out fine. You could try skipping it 😁.
I don’t know much about cooking, but even I could make this! Thanks for the step-by-step!
I don’t know, it was kind of bland. I added some hot sauce, but still not my favorite. 😕
Easy to make. I added capers too. It was kinda salty but still good!
Too many ingredients for my simple taste, just needed salt n pepper.
The recipe’s fine, but I used chicken instead because fish is nasty 😝.
I don’t get it! Fish is delish! 🤷♂️
Chickens r great too, but fish has its own flavor. Anyway, glad u still liked it! 😁
It turned out a bit dry for me. Maybe reduce baking time by a few minutes?
I hate fish, but this actually tasted pretty nice! Who knew tomatoes could save it?
I dunno… I still think fish is gross. Tomatoes or not, it’s just fish.
Wow, that’s surprising! I never thought tomatoes could make fish taste good either. Maybe I’ll give it a shot now!
I used salmon instead. Not sure if that’s right but it was good too!
Salmon sounds like a delicious alternative! Glad you enjoyed it.
The fish was good, but my kids wouldn’t eat it. They only like chicken.
Yummy! Next time I might add some chili for a kick!
I’m not a fish person but this looked good? 🤔 Can I use tofu instead? What do y’all think?
Why do you need oregano? Fish tastes good with just salt. 🙄
But fish can be bland without some seasoning! You gotta try it with oregano, trust me.
I think oregano adds a nice flavor contrast! Salt is good, but herbs can really elevate the dish.
It was okay, but my fish kinda fell apart. Should I change the cooking time?
I used frozen fish fillets instead and it was still good! Thanks for the recipe!
Glad it worked out! I’ll have to try frozen next time. Thanks!
Frozen fish? That’s not the same! Fresh is always better!
Easy recipe! But I used chicken instead of fish. Worked out fine, my kids loved it! 😂
Sounds delicious! Chicken is a great substitute too. Glad your kids enjoyed it! 😄
This was so delicious! The flavor was amazing and the fish came out perfectly flaky. Will definitely make again!
Why is everyone raving about this? It’s just fish and sauce. I honestly expected more.
I get what you’re saying, but sometimes simple is best! This dish is all about the flavors blending together. Not every meal has to be fancy to be good.
I mean, just fish and sauce? Sounds delicious to me! Plus, it’s healthy. Maybe try it before knocking it, yeah?
Yummy!
Baked fish with tomato? Who does that! 🍅 I quartered the tomatoes and used fresh herbs instead. Not bad.
easy to follow and cooks fast! My kids loved it. 🙂
This was absolutely delicious! The flavors blended perfectly. Will make it again for sure!
This was a flop for me. My family didn’t like it at all. Disappointed! 1 star.
I tried this but it turned out too dry. I think I overcooked the fish.
simple. tasty. I added a bit of chili for heat. Yum!
I don’t know about using fish with tomatoes. Seems like a weird combo to me.
I get where you’re coming from, but fish and tomatoes are actually a classic combo in many cuisines! Give it a try, you might be surprised.
Nah, that don’t sound right. Fish should be plain or with butter, not tomatoes! Sounds gross almost.
Fish? With tomatoes? Are we supposed to eat that?
Yes! Fish and tomatoes are actually a great combo. You should give it a try!
This is easier than I thought! Made it in just 30 mins. Will definitely share with my friends.
I mixed the recipe with chicken instead of fish. It was still okay! LOL.
Yum! Just made this for dinner, adding some capers next time! 🤤
Sounds delicious! Capers would add a nice tang! 😍
Too much oregano for my taste. I think I’ll stick with butter next time.
I actually love the oregano in this recipe! It adds such a great flavor. But hey, everyone has their own taste, right?
Yeah, but how can you call this a recipe? Just throw some stuff together, lol.
I think it’s simple but tasty! Sometimes the easiest recipes are the best. 😊