Prepare the ingredients: Start by draining the tuna completely to remove excess liquid. Dice the avocados into medium-sized cubes and place them in a large mixing bowl. Drizzle them immediately with lemon juice to keep them from browning and to give that fresh, tangy kick.

Add the vegetables: Toss in the finely chopped red onion, diced cucumber, and halved cherry tomatoes. Stir gently with a spoon so the avocado doesn’t get mashed — you want nice, chunky pieces in every bite.

Mix the tuna base: Add the drained tuna into the bowl, flaking it gently with a fork so it combines evenly with the veggies. Sprinkle a pinch of salt, black pepper, and garlic powder (if using). Slowly add the mayonnaise or Greek yogurt and drizzle with olive oil. Stir everything together until it’s creamy and well combined, but still light in texture.

Adjust flavor and texture: Taste and adjust seasoning — add more lemon juice for brightness, or a little more mayo/yogurt if you prefer a richer consistency. If you want a subtle heat, sprinkle in a few chili flakes at this stage.

Serve and garnish: Spoon the salad into bowls or serve it over crisp lettuce leaves for extra crunch. Top with chopped parsley or cilantro for freshness and a touch of color. Chill in the fridge for 10–15 minutes before serving if you prefer it cool.