Preheat the oven to 425 F. Line a baking sheet with parchment paper.
Drain and rinse the chickpeas. Dry them well with a paper towel or kitchen towel. Toss chickpeas with olive oil, paprika, garlic powder, and salt and spread them evenly on the lined baking sheet. Bake in the preheated oven for 30 minutes, tossing halfway.
While chickpeas are in the oven, prepare the salad and dressing. Add all dressing ingredients to a powerful blender and blend until smooth. The dressing will be smooth, thick, and creamy. For a thinner dressing, add more olive oil.
Assemble the salad. In a large bowl, add the chopped lettuce, green onion, and sliced cucumber. Add the dressing and toss well to combine. Top with the shredded rotisserie chicken and cooled crispy chickpeas.