To start, whisk together lemon juice and dijon mustard in a small bowl.

Then whisk in olive oil.

Season with kosher salt and freshly ground black pepper.

Next, prepare the ingredients for the salad. Rinse chickpeas well in a strainer, then let sit to drain well.

Wash bell pepper and cucumber, then chop into small, bite-sized chunks.

Peel red onion half, then chop finely.

Combine chickpeas, pepper, cucumber, and red onion in a large bowl.

Drain tuna, and use a fork to pull out of the jar and flake into the bowl with the vegetables.

Drain capers well, then add to bowl.

Stir gently, leaving some small chunks of tuna intact.

Stir in about half of the dressing. Taste, and add kosher salt and freshly ground pepper if needed.

Rinse salad greens, separate into leaves, and pat dry.

Serve spoonfuls of tuna salad into the salad green cups, or on top of greens if you are using loose salad greens.

Drizzle with remaining dressing to serve.