Preheat oven to 400 degrees. Line a baking sheet with parchment paper. In a small bowl, add the harissa paste, lime juice, olive oil and a few pinches of salt. Whisk until combined.
To a sheet pan, add the drained chickpeas, diced eggplant and red onion. Add half of the harissa paste mixture and mix together until everything is covered in the sauce. Smooth it out into one even layer. Arrange the chicken on top. Sprinkle the chicken with a few pinches of salt. Brush the chicken with the harissa sauce and add the any remaining sauce to the chickpeas. Also add any garnish limes to the sheet pan, if you like.
Transfer to the oven to bake for about 35 to 40 minutes, until the chicken is golden brown. Divide amongst plates and garnish with some cilantro.