“Tuna steaks with kale and avocado tomato relish is a mighty big meal. It is perfect for hungry summer days! My generous tuna steaks are marinated in coconut aminos (you can also use tamari if you don’t mind soy), then cooked in a griddle pan to get lovely char-marks. I serve it over a fresh kale salad seasoned with sesame oil. It is a delight when finished with a simple avocado and tomato salsa. High in protein, fibre and so many nutrients!” – Monya
![]()
![]()
Fats of Life® is a keto and low carb recipe blog that I love to run as a hobby in my spare time. I am also the author of the best-selling Keto Kitchen Series of cookbooks. This includes my debut best-seller Keto Kitchen (2020). The fun and exciting Lazy Keto Kitchen (2021). And, the clever and inspiring Budget Keto Kitchen (2022). My 4th cookbook, Quick Keto Kitchen (2023) is as fantastic as the first three, and packed with spectacular, easy creations!
![]()
The links above will take you to Amazon UK. For USA and other countries, see the global Amazon links here: Keto Kitchen ; Lazy Keto Kitchen ; Budget Keto Kitchen ; Quick Keto Kitchen.
![]()
The Glow Factor, 2025 by Penelope Corwin is available worldwide. The image above will link to Amazon UK. For USA and all other countries, click here.
![]()
More on Tuna Steaks with Kale and Avocado Tomato Relish…
Tuna steaks, with their rich flavour and abundant health benefits, are a perfect fit for the keto diet approach. These delectable cuts of fish provide an excellent source of lean protein and essential omega-3 fatty acids, making them an ideal choice for those following the keto lifestyle.

FOLLOW MONYA:
Tuna steaks are not only nutritious but also incredibly versatile in the kitchen. Whether grilled, seared, or baked, they offer a great combination of tenderness and firmness. Their mild taste allows for a wide range of flavour profiles, like I did here with toasted sesame oil.
In this salad, the tuna steaks are served on a bed of massaged kale. Kale can be tough and bitter but massaging it with a little olive oil and salt transforms it into a tender, flavourful delight. The process of massaging kale helps break down its fibres and reduce bitterness, resulting in a more enjoyable eating experience. The dark, leafy greens provide an abundance of vitamins, minerals, and antioxidants, making them an excellent addition to a keto diet.
By combining the deliciousness of seared tuna steaks with the textural appeal of massaged kale, this vibrant and nutrient-dense salad not only satisfies cravings but also supports overall well-being.

It is important to note that to maintain ketosis, it’s essential to track carbohydrate intake and ensure it aligns with your daily macro goals. Consulting with a healthcare professional is advised before making significant dietary changes. Scroll to the bottom to see the full macros and allergens for this Tuna Steaks with Kale and Avocado Tomato Relish, as well as all the Seafood on Fats of Life®.
Tuna Steaks with Kale & Avo Tomato Relish
Per serving
Equipment
Ingredients
For the tuna
- 450 g (15.9 oz) tuna steaks
- 1 TB coconut aminos
- 25 g (0.9 oz) unsalted butter
For the kale
- 100 g (3.5 oz) curly kale, torn into smaller pieces
- 1 TB olive oil
- 1 TB toasted sesame oil
- salt
For the tomato & avo relish
- 1 tomato, finely chopped
- 1 avocado, diced small
- small handful coriander leaves, finely chopped
- 1 lime, halved
- salt and freshly ground black pepper
To finish
- toasted sesame oil, additional drizzle
- sea salt flakes
- 1 red chilli, thinly sliced
Instructions
- Place the tuna steaks into a shallow bowl and pour over the coconut aminos. Toss to coat evenly, cover and leave in the fridge for at least an hour.

- When ready to cook, melt the butter in a griddle pan over high heat and cook the tuna for 2-3 minutes on each side. Set aside to keep warm although it is equally delicious served ambient or even chilled.

- In the meantime, prepare the curly kale which should be torn or chopped into smaller pieces. Place into a large bowl and add the olive oil and sesame oil. Get stuck in with clean hands massaging the mixture. After 15-20 seconds, you will notice how the kale softens and glistens. Season with salt and divide between two plates.

- For the tomato and avocado relish, simply combine the chopped tomato, chopped avocado and chopped coriander. Squeeze over the juice of 1/2 the lime (keeping the remaining half to serve). Season with salt and freshly ground black pepper and mix well to combine.

- Serve the tuna steaks over the kale. Drizzle a little sesame oil over the fish and season with salt flakes. Top with the avocado and tomato relish and finish with the sliced red chillies. If you feel it needs a little more acidity, you still have that 1/2 lime to squeeze over. Yum!
My name is Monya Kilian Palmer. If you loved this recipe, please follow and tag me @mkilianpalmer on Instagram so we can all see your lovely creations!
Nutritional Information per servingCalories 728Kcal / 3046kJ
Fat 44g
Carbohydrates 5.9g
Protein 77g
Allergens
Milk
Sesame
Fish
See all the Seafood on Fats of Life:






Disclaimer: The nutritional analysis, macro and allergen breakdown of the recipes on this site have been manually and carefully calculated using the cloud-based software NUTRITICS®. NUTRITICS® is fully approved by the relevant Trading Standards organizations and is EU and FDA-compliant. The macro calculations are provided as a courtesy to you based on the author's weighing of ingredients when creating the dishes. If Erythritol (a sugar polyol) has been used in any of the recipes, it has already been manually excluded from the final carbohydrate count. The author is a chef - not a medical professional - and this website has been designed to provide you with recipe ideas to suit the low carb lifestyle you have discussed with your GP.
Disclosure: Like many blogs, Fats of Life is part of the Affiliates Program on Amazon. The links to the products recommended here are affiliate links, meaning - at no additional cost to you - the author will earn a small commission if you click through and make a purchase.





1 Comment
Drop me a line if you have any questions or comments about this recipe. I will do my best to reply as soon as possible! Monya xxx