In a medium bowl, mash the chickpeas using a fork. Add celery, onion, mayonnaise, 1 tsp mustard, 1 tbsp lemon juice, lemon zest, and dill until combined.
Add greens to two bowls. Top with chickpea “tuna” and avocado slices.
In a small bowl whisk together the juice of 1 lemon, 1 tsp mustard, olive oil, salt and pepper. Drizzle over salads and enjoy!