DO-AHEAD TIP: Marinate chicken for 20 minutes (see recipe).
In a large bowl, combine 3 tablespoons of olive oil, the harissa, 3 cloves of minced garlic, and juice of 1 lemon, the mint, salt and pepper.
Add chicken and turn to coat with marinade; cover and refrigerate for 20 minutes.
In a food processor or blender, add chickpeas, remaining 3 tablespoons of olive oil, juice of remaining lemon, cayenne pepper, cumin and cilantro; pulse for 1 minute or until well until combined.
On an indoor grill pan over medium-high heat, grill chicken for 8 minutes per side or until juices run clear.
Serve chicken with chickpea puree.