Combine all spices (garlic powder, onion powder, paprika, cumin, turmeric, coriander, cinnamon, cloves, cardamom, and oregano) in a small bowl, then whisk together with lemon juice, olive oil, yogurt, salt, and pepper to create a cohesive marinade. Cut chicken thighs into 1-inch chunks and place in a large bowl or resealable bag. Pour the marinade over the chicken, ensuring all pieces are well coated. Let marinate for at least 30 minutes at room temperature, or up to 4 hours in the refrigerator for deeper flavor development—I find the longer marinating time really helps the spices penetrate the meat.
While the chicken marinates, start cooking the rice according to package directions (typically 15-20 minutes for basmati rice). While the rice cooks, prepare the fresh components: dice the cucumber into 1/2-inch pieces, halve the cherry tomatoes, and finely mince the red onion. In a bowl, combine the diced cucumber, tomatoes, red onion, fresh dill, lemon juice, and salt to create the fresh salad component. Set aside until ready to assemble.
Preheat oven to 425°F. Transfer the marinated chicken from Step 1 with all its juices into a roasting pan or large baking dish (9x13 inch or similar). Arrange in a single layer for even cooking. Bake for 40-45 minutes until the internal temperature reaches 175°F. Then switch the oven to broil and broil for 2-3 minutes to lightly char and caramelize the exterior. This step builds incredible flavor through the Maillard reaction.
While the chicken roasts, prepare the creamy sauce. Mince the garlic cloves very finely and set aside. Grate the small cucumber and squeeze it dry in a clean kitchen towel—this step prevents the sauce from becoming watery. In a bowl, combine the yogurt, grated cucumber, lemon juice, lemon zest, minced garlic, fresh dill, fresh mint, and salt. Stir until smooth and well combined. I always recommend using thick, full-fat yogurt like Fage because it creates a more luxurious sauce.
Remove the roasted chicken from the oven and let it rest for 10 minutes—this allows the juices to redistribute throughout the meat, keeping it tender and moist. While the chicken rests, drain the pan juices into a measuring cup. Fluff the cooked rice from Step 2 with a fork, then stir in 1/2 cup of the reserved pan juices to add savory depth and moisture to the rice.
Divide the seasoned rice from Step 5 among serving bowls as the base. Top each bowl with portions of the rested chicken from Step 5, the fresh salad mixture from Step 2, a generous dollop of the tzatziki sauce from Step 4, and any additional fresh herbs or garnishes you'd like (such as crumbled feta, extra dill, or pomegranate seeds). Serve immediately while the chicken is still warm.