This easy, healthy tuna bake in tomato sauce is made with butternut squash, spinach and a crumbly topping of feta. It's quick and easy to make and a delicious way to serve canned tuna.
This healthy tuna bake with tomato sauce is brimming with vegetables, full of flavour and has under 200 calories per serving. The ingredients are a combination of tangy, savoury and sweet flavours which together produce a delicious dish.
For the topping I used (a moderate amount of) feta cheese which becomes soft and mellow when roasted and makes a delicious addition to this dish.
The advantage of making a tuna bake without pasta is that it becomes extremely flexible. You could serve it with either pasta, quinoa, rice, potatoes, couscous or even on its own if you are looking for a low carb version of this classic.
Healthy tuna bake ingredients and substitutions
- Tuna: use the fish as well as some of the brine.
- Tomatoes: from a can.
- Tomato puree: adds richness to the sauce.
- Onion: use any.
- Bay leaf.
- Spinach: fresh is best.
- Butternut squash: use another squash variety or sweet potato if preferred.
- Feta: crumbled or cubed.
- Olive oil.
What type of tuna to use
Use tuna chunks in brine (or spring water) rather than in oil. This is mainly because you will need to add some of the brine into the casserole. Another advantage of using tuna in water rather than oil is keeping the calories down (you might also like my healthy, creamy tuna pate).
Equipment you need
- Large non-stick pan for frying the butternut squash.
- Medium saucepan with lid for making the tomato sauce.
- Medium size casserole dish (5-6 cm /2 inches deep).
Step-by-step recipe instructions
Preheat the oven to 375 F/ 190 C/ gas mark 5.
1.To make the sauce start by frying the onion and garlic with 1 tablespoon of oil and the bay leaf for 3-4 minutes until softened, stirring occasionally.
2. Add the tomatoes, tomato puree, brine from 1 tuna can, season, cover and cook gently for about 7 minutes.
3. In the meantime fry the butternut squash in 1 tablespoon of oil over a fairly high heat for about 7-8 minutes until softened and lightly browned. (Alternatively roast the squash).
4. Place in the casserole dish. In the same pan heat up the spinach and cook for about a minute until it's reduced in size.
5. Add the spinach mixture into the tomato sauce and stir well to combine (remove the bay leaf). Adjust the seasoning if necessary.
6. Scatter the tuna chunks over the squash.
7. Spoon the tomato sauce over the tuna, scatter over the feta, drizzle a little oil, sprinkle some paprika and bake in the centre of the oven for 30 minutes. If the feta starts to brown too much cover loosely after 20 minutes.
8. Remove your tomato tuna bake from the oven and serve!
Serve this recipe with pasta, potatoes, rice, quinoa, couscous or a slice of crusty bread (there'll be lots of sauce to soak up!). Sprinkle fresh herbs, such as chives or parsley over the top just before serving.
Can I make this recipe ahead
Yes, you can! This is what I love about this tomato tuna bake. You can prepare the entire dish the night before and bake the next day.
Top tips for making tuna bake without pasta
- Use tuna in water rather than oil (you will need to use some of the water in the recipe).
- The spinach needs to be fried very briefly. Once it wilts it is ready to combine with the sauce.
- Fry cubed butternut squash until lightly browned and softened before placing in the casserole dish.
- To save time you can cook the tomato sauce and butternut squash simultaneously.
- Best served immediately.
- Refrigerate leftover low carb tuna bake in an airtight container for up to 3 days.
- Freezing: Once cooled transfer into an airtight container and freeze for up to 3 months. To defrost place in the fridge overnight then reheat in the microwave.
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Keep in touch!
Have you made this healthy tuna bake recipe? I'd love to know how it turned out for you. Let me know in the comments below, thanks!
Healthy Tuna Bake (No Pasta)
- Large non-stick frying pan
- Medium sized saucepan with lid
- Medium sized casserole dish, approx. 6 cm/2 inches deep
- 1 pound (450 g) butternut squash peeled, cubed weight, see *Notes below
- 1 onion finely chopped
- 2 garlic cloves finely chopped
- 1 bay leaf
- 7.94 ounces (225 g) tuna (2 small cans) in brine (reserve the brine from 1 can)
- 1x14.11oz can (400 g) chopped tomatoes
- 2 tablespoons tomato puree
- 3.53 ounces (100 g) spinach finely chopped
- 3.53 ounces (100 g) feta crumbled or cubed
- 2 tablespoons olive oil plus more for drizzling
- ½ teaspoon fine sea salt plenty of pepper and paprika for sprinkling on top (optional)
- Fresh parsley or chives for garnish plus paprika for sprinkling on top
- Preheat the oven to 375 F/ 190 C/ gas mark 5.
- In a medium saucepan heat up 1 tablespoon of oil, add the bay leaf, garlic and onion and cook on a low heat for 3-4 minutes, stirring occasionally. Add the tomatoes, tomato puree, brine from 1 tuna tin, season to taste, cover and simmer for 7 minutes.
- In the meantime in a large non-stick pan heat up 1 tablespoon of oil and fry the squash cubes on a high heat for about 7-8 minutes stirring often until softened and lightly browned. Remove from the heat and place in your oven dish.
- In the same frying pan heat up the spinach and cook over a fairly high heat until reduced in size, for about 1 minute, stirring all the time. Stir the spinach mixture into the tomato sauce. Adjust the seasoning if necessary.
- Spread the tuna over the squash, pour the sauce over the whole thing, top with feta, drizzle with a little oil, sprinkle some paprika and bake in the centre of the oven for 30 minutes. If the feta starts to brown too much cover loosely after 20 minutes.
- Remove from the oven and serve. Garnish with parsley and enjoy with pasta, quinoa, potatoes, couscous, crusty bread or simply on its own.
- Use tuna in water rather than oil (you will need to use some of the tuna water in the recipe).
- The spinach needs to be fried very briefly. Once it wilts down it is ready to combine with the sauce.
- *Tips for preparing the butternut squash.
- Fry the butternut squash cubes (in a non-stick pan) until lightly browned and softened.
- Serving: Serve with pasta, potatoes, rice, quinoa, couscous or slice of crusty bread (there'll be lots of sauce to soak up!). Sprinkle over fresh herbs, such as chives or parsley.
- Best served immediately.
- Refrigerate leftover tuna bake in an airtight container for up to 3 days.
- Freezing: Once cooled transfer into an airtight container and freeze for up to 3 months. To defrost place in the fridge overnight and reheat in the microwave.
*Nutritional information is automatically generated and should be considered as an estimate.
**A note about baking: If using a fan-assisted oven refer to your appliance's instructions and adjust the temperature accordingly.