Heat your grill to medium heat, and place a grill basket onto it while heating (this helps the veggies cook faster if the basket is hot!) Rub both the grill and grill basket generously with olive oil.
Place the eggplant and zucchini into a large bowl and toss with the olive oil and a pinch of salt and pepper until evenly coated. Set aside.
Combine the cumin, cinnamon, paprika and allspice. Rub evenly onto both sides of the chicken and sprinkle with salt and pepper.
Dump the veggies into the grill basket, and place the chicken onto the grill beside the basket. Cook the chicken until no longer pink inside, about 10-12 minutes total, flipping once half way through the cooking time. When you flip the chicken, give the veggies a good stir.
Transfer the cooked chicken to a plate and cover to keep warm while the veggies finish. Turn the grill heat up to medium high and cook the veggies for another 7-10 minutes until nice and charred, giving a stir half way through the cooking time.
Transfer the cooked veggies back into the large bowl and add in the tomato, cucumber, cilantro and mint. Toss to coat evenly.
Add in the fresh lemon juice and toss to coat. Finally, add in the tahini and toss until the veggies are nice and creamy.
Divide the veggies and chicken between two bowls, followed by the olives and pistachios.