How to Make It
In a medium bowl, whisk the yogurt, lime juice, garlic, tahini, turmeric and 1 tablespoon of olive oil. Fold in the cucumber and mint and season with salt and pepper.
Light a grill or preheat a grill pan. Generously brush the chicken thighs with olive oil and season with salt, pepper and chipotle chile powder. Grill the chicken over moderately high heat, turning occasionally, until lightly charred outside and cooked through, 8 to 10 minutes. Transfer the chicken to a carving board and let rest for 5 minutes.
Cut the chicken into bite-size pieces and transfer them to a large bowl. Add half of the cucumber yogurt and toss well. Season with salt and pepper. Transfer the yogurt chicken to plates, garnish with sliced scallions and serve with warm flatbread or steamed rice, passing the remaining cucumber yogurt at the table.