Prepare the dressing: In a small jar or bowl, combine the lemon juice, olive oil, and Dijon mustard. Pop the lid on and shake vigorously until the dressing looks thick and emulsified — it should smell bright and tangy.

Prep the vegetables: Dice the avocado into even, bite-sized cubes — you want them to hold their shape, not turn to mush. Finely chop the red onion so it’s almost translucent, then halve the cherry tomatoes and dice the cucumber. The cucumber should feel crisp and cool in your hand.

Flake the tuna: Drain the tuna well and tip it into a large salad bowl. Use a fork to break it into flakes — you’re looking for a mix of small chunks and finer shreds, not a paste. The tuna should look light and fluffy.

Combine everything: Add the diced avocado, red onion, cherry tomatoes, and cucumber to the bowl with the tuna. Pour over the dressing and toss gently with salad servers until everything is evenly coated. The avocado should just start to soften against the other ingredients, but still hold its shape.

Season and finish: Sprinkle over the chopped herbs, then season generously with salt and pepper. Give it one more gentle toss — the aroma of lemon and herbs should be fresh and inviting.

Serve or chill: If serving immediately, pile the salad onto a bed of rocket or salad leaves. The leaves will wilt slightly from the dressing, turning a deeper green. If you’re prepping ahead, cover and refrigerate for up to 2 hours — the flavours will meld beautifully.