In a large salad bowl, add cucumber, red onions, bell pepper, avocado, drained tuna and chives.
In a mason jar, pour the freshly squeezed lemon juice, olive oil and salt and black pepper. Whisk everything together until combined.
Taste to check the seasoning and pour over the salad.
Toss to combine and enjoy!
If you like this recipe you can make also this Shrimp Avocado Cucumber Salad, which is also super easy to make and delicious. But instead of tuna, you will use shrimp. Or if you're looking for another high-protein salad, I'm sure you'll love this delicious Shrimp Tomato Salad recipe. It's fresh, healthy, and quick and easy to make too!