Preheat your oven to 400°F (200°C) and line a small baking sheet with parchment paper.
Drain and rinse the chickpeas, then pat them very dry with a paper towel to ensure they get crispy.
Toss the chickpeas with 0.5 tbsp of olive oil, a pinch of sea salt, and a pinch of black pepper on the baking sheet.
Roast the chickpeas for 20-25 minutes, shaking the pan halfway through, until they are golden and crunchy.
In a small bowl, whisk together the Greek yogurt, lemon juice, lemon zest, garlic powder, and the remaining 0.5 tbsp of olive oil to create the dressing.
Drain the tuna and place it in a medium bowl, flaking it with a fork, then stir in the yogurt dressing until well combined.
Place the baby arugula in a large serving bowl and top with the diced cucumber and sliced avocado.
Add the zesty tuna mixture to the center of the greens and top with the warm, crispy chickpeas.
Season with the remaining sea salt and black pepper before serving immediately.