Prep the produce. Halve the tomatoes, slice the cucumber, and thinly slice the red onion. Chop a small handful of fresh herbs. Halve and pit the avocado, then scoop and dice it just before assembling so it stays bright.

Drain and fluff the tuna. Open the can, drain well, and use a fork to break it into chunky flakes. If using tuna in olive oil, you can reserve a teaspoon of the oil to enrich your dressing.

Make the dressing. In a small bowl, whisk together 2 tablespoons olive oil, the juice of half a lemon, 1 teaspoon Dijon mustard, a pinch of salt, and cracked black pepper. For extra zing, add a little lemon zest. If you like it creamy, whisk in 1 tablespoon Greek yogurt or mayo.

Build your base. Add a large handful of mixed greens to a bowl. Scatter the cucumbers, tomatoes, and onion over the top. Sprinkle with herbs.

Add the tuna and avocado. Spoon the tuna onto the greens and nestle the avocado cubes around it. Season the avocado lightly with salt to bring out its flavor.

Dress and toss gently. Drizzle the dressing over the bowl. Toss lightly with tongs or a fork, just enough to coat without smashing the avocado.

Finish with texture and extras. Add any optional toppings you like—capers for brine, pumpkin seeds for crunch, feta for creaminess, or cooked quinoa to make it heartier. Taste and adjust salt, pepper, or lemon.

Serve immediately. This bowl tastes best fresh, when the greens are crisp and the avocado is perfectly creamy.