01 - Combine olive oil, cumin, coriander, smoked paprika, turmeric, cinnamon, cayenne pepper, minced garlic, salt, black pepper, and lemon juice in a large bowl. Add chicken thighs and toss to coat thoroughly. Cover and refrigerate for at least 20 minutes or up to 2 hours to develop flavor.
02 - Rinse the basmati rice under cold water until the water runs clear. In a saucepan, combine rice, water, salt, and olive oil. Bring to a boil over medium-high heat, then reduce the heat to low, cover, and simmer for 12 to 15 minutes until the water is absorbed and rice is tender. Fluff with a fork and keep warm.
03 - Preheat a grill pan or skillet over medium-high heat. Remove chicken from marinade and cook for 5 to 6 minutes per side until golden brown and fully cooked. Allow the chicken to rest for 5 minutes before slicing into strips.
04 - While the chicken cooks, dice the cucumber, halve the cherry tomatoes, thinly slice the red onion, chop the parsley, and cut the lemon into wedges. Arrange mixed salad greens.
05 - Divide the cooked rice evenly among four bowls. Top each with a portion of salad greens, sliced chicken, hummus, cucumber, cherry tomatoes, red onion, and parsley. Sprinkle sumac over the vegetables if desired. Serve with lemon wedges on the side.
06 - In a small bowl, mix Greek yogurt, lemon juice, chopped mint, salt, and pepper. Drizzle the sauce over the assembled bowls if preferred.