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You have to try this fish casserole! I knew it was a winner with the first bite. The recipe was given to us by my Mama-in-law and her friend shared it with her. When a recipe gets shared over and over, you know it’s good. Seriously, this is MOUTH-WATERING! It also tastes healthy and light. The tilapia is juicy and flaky without a hint of fishiness.
The sweet veggies complement it beautifully. If you aren’t a fan of tilapia, you can easily substitute your favorite fish and get the same delicious results. I want more! We ate it up real quick! This dish is perfect for company. It is easy to make, smells and tastes delicious and your guests and family will love it.
Tilapia Ingredients:
2 lbs (about 6-10 count) Tilapia fillets, thawed
Olive Oil to saute
1 Tbsp ketchup (several readers had great results with Sriracha instead of ketchup)
1 Tbsp mayo
Marinade Ingredients:
2 large eggs
1 cup buttermilk
2 Tbsp soy sauce
1/2 tsp Salt and 1/8 tsp Pepper
Vegetable Ingredients:
2 medium bell peppers (red, orange, or yellow)
2 medium/large carrots, julienned or grated
1 medium onion
How to Make Tilapia and Vegetable Casserole:
1. Whisk together marinade ingredients. Combine with tilapia in a large ziploc bag or bowl and marinate in the fridge at least 1 1/2 hours.
2. Slice onions into thin half circles, slice bell pepper into thin strips and julienne or grate carrots. In a large skillet over medium/high, heat 2-3 Tbsp oil and saute onions for 3 minutes or until softened. Add sliced bell peppers and carrots and saute another 4-5 min or until softened. Remove from pan and set veggies aside.
3. Once fish is done marinating, drain and discard marinade. In the same empty skillet over medium/high, add 2-3 Tbsp oil and saute fish lightly on the skillet just until golden on the outside (about 2 min per side) – it’s ok if it’s not cooked through completely at this point. Also, it probably would have been easier to turn the fish on a non-stick skillet :-O.
4. Layer the casserole dish with 1/2 of the vegetables on the bottom. Place fish over the vegetables. Stir together 1 Tbsp ketchup and 1 Tbsp mayo and brush this mixture evenly over the top of the fish. Cover fish with remaining veggies. Sprinkle the top with salt and pepper to taste then cover tightly with foil or lid and bake at 375˚F for 15 min.
Tilapia and Vegetable Casserole Recipe

Ingredients
Tilapia Ingredients:
- 2 lbs about 6-10 count Tilapia fillets, thawed
- Olive Oil to saute
- 1 Tbsp ketchup, several readers had great results with sriracha instead of ketchup
- 1 Tbsp mayonnaise
Marinade Ingredients:
- 2 eggs
- 1 cup buttermilk
- 2 Tbsp soy sauce
- 1/2 tsp Salt and 1/8 tsp Pepper
Vegetable Ingredients:
- 2 medium bell peppers, (red, orange or yellow)
- 2 medium/large carrots, julienned or grated
- 1 medium onion
Instructions
- Whisk together marinade ingredients. Combine with tilapia in a large ziploc bag or bowl and marinate in the fridge 1 1/2 hours.
- Slice onions into thin half circles, slice bell pepper into thin strips and julienne or grate carrots. In a large skillet over medium/high, heat 2-3 Tbsp oil and saute onions for 3 min or until softened. Add sliced bell peppers and carrots and saute another 4-5 min or until softened. Remove from pan and set aside.
- Once fish is done marinating, drain and discard marinade. In the same empty skillet over medium/high, add 2-3 Tbsp oil and saute fish lightly on the skillet just until golden on the outside (about 2 min per side) - it's ok if it's not fully cooked through at this point.
- Layer the casserole dish with 1/2 of the vegetables on the bottom, then Place fish over the vegetables. Stir together 1 Tbsp ketchup and 1 Tbsp mayo and brush this mixture evenly over the top of the fish. Cover fish with remaining veggies. Sprinkle the top with salt and pepper to taste then cover tightly with foil or lid and bake at 375˚F for 15 min.
♥ FAVORITE THINGS ♥
Shown in this post: (nope, no one paid us to write this; just stuff we love):
* It’s so handy to have multiple sizes of liquid measuring cups.
* This is my favorite baking casserole dish. I love that it has a lid!
* We search high & low for a perfect julienne slicer. This Swissmar is it!
* If using a slicer or mandolin, you have to try these safety gloves!
Natasha, what kind of frying pan did you use to saute the fish? It doesn’t look like a non-stick pan in the picture. I am trying to get away from Teflon but every time I try to saute fish in a stainless steel pan, it sticks mercilessly and I end up with a mess.
Katie, my was fairly sticky too, that’s why I recommended non-stick pan.
Just made this casserole. It is soooo delicious!!! My husband who doesn’t like bell peppers loved them on this fish! Thank you Natasha for another great recipe.
Vita, thank you so much for such a great review and you are welcome :).
holy crap this dish looks amazing… It took everything in my power not to lick my screen!! Thank you for posting.. I found this on Pinterest.
Lol, you are welcome Alexandra :D, enjoy.
Nice recipe. Thank you. Have a good shower and take care.
Thank you so much Liz 🙂
Thanks again Natasha for another beautiful simple recipe.
This looks great!! My 18 yr old is pretty much a vegetarian and she loves eating Tilapia and other kinds of seafood. This she will surely love to try!! Also I love the family photos.
Sweet 16 such age of innocence and youth!
Oh awesome!! I hope she loves this casserole! Thank you so much for your sweet comment. My sis-in-law is also vegetarian 🙂
Natasha, thank you for a great recipe. WE LOVE FISH AND VEGIES, so that’s a perfect dish for us, gotta try it ASAP. My mouth is watering now :))
What would you recommend using instead of buttermilk? Can I use some sour cream? Or can I just omit it as all? Thank you in advance for your reply.
The buttermilk in the marinade is really just to pull any fishy scent out of the fish. Milk would probably be an ok substitute, or my Mama-in-laws friend has also marinated in just soy sauce. If you aren’t concerned with “fishiness,” you could just season the fish and saute it :).
Looks yummy! Is it ok if it marinates for more then 1 1/2 hours
Yes – but if your filets are much smaller and thinner than the ones photographed, you might not push it past 2 hours.
This recipe looks amazing. Other than Tilapia, what other fish would work well with this?
One of my readers has reported good results with salmon. Cod, trout or bass would all probably work pretty well.
Thank you. Keep the recipes coming! Your blog is very inspirational!
Hi Ellen, thank you so much for the encouragement 🙂
This looks really interesting. I’ve never baked fish like this before. Definitely trying this!
Oh it’s wonderful! I hope you LOVE it! 🙂
Oooh was that delicious!
I prepared it without marinating and saute the fish (what effect has it actually?) and added olives.
– Wkusnjatina! –
The marinade removes any fishiness from the fish :). I’m so happy you loved the recipe!
My husband is the fish chef in our house. This looks like one our whole family would enjoy.
Hi Kathy! I hope you all love it as much as we do 🙂
I am so excited to see this recipe, Natasha! My best friend’s mama used to cook fish like that and I remember loving it!!! You are right, it does taste incredibly light, healthy but YUMMY! My husband and kids don’t do bones so this will be perfect. 🙂 Pinning it and making it soon.
I’m happy to report that we didn’t find a single bone :). I hope you love it and thanks so much for pinning it!
I tried this tonight. It was super delicious! However I think I’m going to try a different fish next time. We served it with rice and it was incredible. My husband when came home after work said I’m not really hungry but he actually went in for seconds. I told him its Natasha’s kitchen new recipe. Thank you, I love your site.
I’m so happy you loved the recipe! 🙂 Thank you for the great review. Do let me know what fish you try next. I’m super curious! 🙂
What a beautiful casserole! I love the colors from the vegetables, makes it seem so festive. I pinned it, and I really hope I remember to go back to this recipe next time I want to make fish. 🙂
Thank you so much for pinning! I sure appreciate it 🙂 I hope you LOVE the casserole 🙂
Oh Thankyou Natasha so much for the recipe. I’ve been looking for something like this for so long. I’ve surch YouTube couldn’t find anything of this style. I’m sure we going to love it.
Just one question do your once the marinate completely with cold water?
Thanks again.
I’m planing to do this next week
Are you asking if I rinse the fish first? Yes I do rinse my meats and fish in cold water usually before using them, just in case. 😉
Wow, what a coincidence. I just did something very similar with tilapia (love that fish, even kids love it) yesterday. I don’t even bake mine. I just layer the veggies (this time I only used onion and carrots), then the fish and veggies again in the same pan that I cooked the fish and veggies to prep them. And I don’t marinade either. But I like your idea of baking, that’s an awesome idea to cook for bigger groups.
The marinade is nice to make sure the fish doesn’t have any hints of fishiness (just in case) :). Your casserole sure sounds good and easy too! Thanks for sharing your method 🙂
I got to try this! We do a lot of fish but mostly just really simple and I’m always on the look out for yummy fish recipes. This one looks awesome! I love the combination of flavors.
I love fish dishes too, but we don’t eat fish nearly often enough :). Thanks Katya 🙂
Mmmm! I love tilapia! Can’t wait to try this! Where do you get your tilapia fillets?
I hope you love it! I purchased these at Costco. They are a little more expensive there than other stores, maybe it is because they are tilapia loins and a little bit larger than the fillets you would purchase at say a Walmart? I’m not sure. 🙂
I do a very similar dish all the time. I don’t like tilapia, so I use salmon or swai (these two don’t taste fishy at all, so I skip the marinade ). Sometimes I put sliced potatoes under the fish, so I don’t have to cook side dish. This is my go to recepe when I need to cook something fast and I’m so happy you posted it.
Thanks for sharing how you make yours. Sounds delicious!! Do you use the same veggie mix?
pretty much the same mix. I add celery sometimes. I actually made it today with salmon and used your garlic/lemon/dill sauce on the salmon and put the veggies on top. Thank you so much for this! Your blog is great, I’m finding so much inspiration here. Thank you for taking the time to post the recipes
I’m so happy you are enjoying the site! Celery seems to make everything taste better 🙂 I love your idea for using salmon in a casserole!
With the sliced potatoes on bottom… How do you adjust the cooking time?..
The potatoes would have ro be nearly-cooked or they wont cook through in the oven. If you bake longer, your fish could become tough and dry.
I slice potatoes, toss them with olive oil, salt, pepper, garlic powder and arrange in the baking dish in one layer. I start baking at 400 F 20-25 minutes before fish goes in.
With the sliced potatoes on bottom… How do you adjust the cooking time?..
Looks very yummy. What do you serve on the side with this dish?
Thank you
Dorina, this dish pairs well with a lot of different food. You can serve it with rice, quinoa, buckwheat, mashed potatoes. We ate it with mashed potatoes :).
I’ve been waiting for this recipe since you posted a teaser on IG. It’s finally here. My grandma even bragged about her daughter in law and her new fish casserole. I think this is the same recipe. I can’t wait to make it. Defrosting fish as I type this.
Do let me know if it is the same or similar! I hope you totally love it! 🙂
I am so excited to make it. Thanks for the awesome recipies, Natasha!! I love ur recipies!
Thank you so much Alina! I’m so happy to hear you are enjoying the recipes 🙂